Problem after Pie update: black screen on certain apps the SECOND TIME it is awaken from sleep

[khpy1azn]

This question has already been posted on several other sites, but without an ideal solution.

I just updated to Android Pie yesterday (long overdue monthly update from last year), and this problem started occurring. So far it only happens to two types of apps: browsers (chrome, firefox, opera beta) and games (pokemon go, modern combat 5, etc).

What happens is that when I have the app on the screen, I press the power button to put the phone to sleep then press it again to wake the phone up...it goes back to the app fine. But if I do the same thing the SECOND TIME (sleep then wake), the screen turns black (status bar and navigation bar still visible). I have to switch the app away then switch back, for the screen to show up. With games, the black screen is full-screen; but with browsers, the black screen is restricted to the webpage area.

I never use any form of lock screen. I tried to add a "swipe to unlock" lockscreen and the problem doesnt occur. So the problem only happens when the phone wakes from sleep and go straight to the app without any lock screen in between. Also, I would say that more than 90% of the time it happens during the second sleep-wake action, but sometimes it can happen on the third or fourth.

I have now installed all the overdue monthly system updates to the latest version (april 2019) and the problem still persists. Anyone has a solution? Thank you.

[mahesh911]

Well .. this is not that kind of a serious issue. It happens because of the way interaction between running application on memory and going deep sleep. I tried it doesn't happen for me and only one time browser hanged for a second or two then resumed. For games black screen might appear when trying to resume the gaming session. It's kind of android thing.

Solution is I recommend that before going to sleep, press home button to home screen and then switch to sleep and when wakes up go to recent and resume your application.

In case of gaming, first pause the game, return to home screen and sleep, then wake up, go recent and resume game.

It looks like when I tried, the problem occurs only if u immediately try to wake up phone 2nd or 3rd time after u put to sleep... If u give enough time for the phone to manage your session , it will work without problem. 

[khpy1azn]

It never happened when I was on android 8, and it certainly is a big issue. Also for me it doesnt have to be successive sleep-wake within a short time frame to induce this problem.

Problem is e.g. for games like pokemon go, we need to constantly off and on the screen. And having black screen like this and having to constantly return to the home screen is unacceptable.

I already figured out a workaround (as posted here: https://forums.androidcentral.com/ask-question/957336-black-screen-certain-apps-second-time-awaken-s...).

[mahesh911]

Ok so good that issue settles in for you.. it will be helpful to anyone who play Pokémon games ..  I don't see problem with browsers.. I tried wake, sleep about 5 times in a row.. always returned to where I was..  mine is pin locked with fingerprint locking with registered 3 fingers. When I unlock it unlocks as usual and return to browser. 

Think rest of games will be fine unless it's Pokémon type...

Have a good day....

[khpy1azn]

like i said before, the problem doesnt occur with a lock screen, only when going straight from sleep to app. Also, like i said...all games have this problem. I tried mc5 and two other games I downloaded long ago but never played (7 years from now, Innocent), all have the same problem.

Now i realise another problem is that the gps is not working properly anymore. Tried different settings but not solving the problem. Determining location using GPS only doesnt work, and using GPS + other tools doesnt update location properly (stuck in one place forever).

[mahesh911]

---

@khpy1azn wrote:

like i said before, the problem doesnt occur with a lock screen, only when going straight from sleep to app. Also, like i said...all games have this problem. I tried mc5 and two other games I downloaded long ago but never played (7 years from now, Innocent), all have the same problem.

Now i realise another problem is that the gps is not working properly anymore. Tried different settings but not solving the problem. Determining location using GPS only doesnt work, and using GPS + other tools doesnt update location properly (stuck in one place forever).

---

Then the solution is putting a lockscreen.  

For GPS , try calibration and try to locate without connecting to WiFi network. Calibration can be done in Google maps as well..

[khpy1azn]

Putting a lockscreen is a big hassle and waste of time. My phone is always with me so there's no security reason to do so. As for the gps, I tried several methods and it seems to be better now. Not smooth like android 8, still have lags and jumps but better than not working at all. Thank you.

[mahesh911]

---

@khpy1azn wrote:

Putting a lockscreen is a big hassle and waste of time. My phone is always with me so there's no security reason to do so. As for the gps, I tried several methods and it seems to be better now. Not smooth like android 8, still have lags and jumps but better than not working at all. Thank you.

---

Lockscreen hassle and time waste? I have nothing to say.

Fingerprint unlocking happens instantly like u do without lockscreen.. if u can sacrifice some seconds u can fix this issue for good.

Sometimes repeated GPS calibration needed to improve the accuracy to prevent position jumping here and there on the map.  It will b fine eventually..

TC

[khpy1azn]

fingerprint option is no longer in my settings. I realised that after I updated to pie, but im not sure when it disappeared. If I go to settings -> support, there is an option to test fingerprint sensor. But after i put my finger on the sensor nothing happens.

And lock screen is indeed a big hassle. Its several seconds alright, but if you times that with the frequency... really wasting a lot of time. Like i said, I found a workaround to double tap the screen to turn it off, with the option to display animation/black screen before it turns off, hence solving the problem. Now I just need to readjust my muscle memory cuz im used to using the power button. But I will get a new phone soon anyway...looking at oppo reno 10x zoom. All my previous phones have been from sony, and lots of my family members also use sony under my recommendation. But that was years ago, sony phones are really not up to standard and way overpriced nowadays.

[mahesh911]

---

@khpy1azn wrote:

fingerprint option is no longer in my settings. I realised that after I updated to pie, but im not sure when it disappeared. If I go to settings -> support, there is an option to test fingerprint sensor. But after i put my finger on the sensor nothing happens.

And lock screen is indeed a big hassle. Its several seconds alright, but if you times that with the frequency... really wasting a lot of time. Like i said, I found a workaround to double tap the screen to turn it off, with the option to display animation/black screen before it turns off, hence solving the problem. Now I just need to readjust my muscle memory cuz im used to using the power button. But I will get a new phone soon anyway...looking at oppo reno 10x zoom. All my previous phones have been from sony, and lots of my family members also use sony under my recommendation. But that was years ago, sony phones are really not up to standard and way overpriced nowadays.

---

Hmm alright... It's your preference that counts... Atleast u solved your problem. But I didn't expect that leads to another issue of missing fingerprint scan. It's been reported before and I think that's probably related to regional build servers which might have given wrong build or some settings that disables it during the upgrade.. like windows 10 update bug .  XZ premium is an amazing phone but can't believe lots of users had issues .. At some point u can try reinstalling stock firmware to fix fingerprint scan issue. Meanwhile try clearing cache and data of fingerprint ASM and fingerprint extension service in the system app list and restart to see if it enables fingerprint option. 

And eh if moving from Sony, I recommend Samsung than oppo.  Ya sure Chinese manufacturers attract by lot of never before features. it's upto u...