ClearAudio+ in Walkman app does not work

[Tournesol]

My Z1 had problem in voice quality during call, so I sent it for warranty repair, and it came back to me with the note saying the latest software version was installed. Now the ClearAudio+ sound enhancement is not working but strangely only when playing FLAC files (saved in Micro SD card). MP3 and MP4 files has no issues and as you all know the effect of this sound enhancement is so obvious. When I turn on and off the ClearAudio+ while playing FLAC songs, it makes absolutely no change in sound quality, which suggest this functionality is not working at all.

Even more strangely, after factory reset the phone, it works even with FLAC files but as soon as start setting it up, such as sign in with google account and install some apps from playstore, it stops working. It's interesting that I only installed the apps that used to be installed on this phone before sent to repair, and it was funcitonal perfectly. Android version is 4.3 and Walkman app version is 7.15.A.0.2 (which is not the latest). I checked the software update but even when I connect to PC by PC companion the update for Walkman does not show up. I have a feeling it has something to do with installing newer version of Walkman app BEFORE Android update to 4.3, but there is no way to try it. 

I also have Xperia Z and installed exactly the same apps and played the FLAC files on the same SD card, but it works without any problem, and the effect of CleaAudio+ is really obvious. On Z, the Walkman app version is 8.1.A.0.3.

Anyone ever had similar issue? I searched the web but didn't find a single case similar to this. Sony Australia advised that since this phone has already been repaired once, I can no longer cliam warranty repair but Sony will be happy to look into it and I can return it to the retailer, but I waited for more than 1 month and half for the 1st repair, and i applied really expensive tempered glass film on both side, so I do not want to lose them if I can. Any help/comment will be appreciated.

[mode893]

As the title suggests,  the equalizer stops working when FLAC tracks are played via bluetooth streaming with my MW1. This is super irritating, please fix ASAP, thanks.

[yasser_alghamdi]

I have the same problem .. I do every thing to fix it and nothing change

Finally.. I downgrade it to 290

[thegios]

I have same problem when playing music with Play Music app: equalizer settings do not work.

On xda other are reporting the same problem and there's also a flashable zip for rooted device fixing this problem.

[Tournesol]

Just bought Z2 (D6503) in Australia directly from Sony. All is fine but one serious problem - The sound quality when listening to music with Walkman app through earphone is significantly worse than Z1 or Z. I use the same music files saved in micro SD card and tested with the same earphone, and the difference is substantial like everyone could easily tell the difference and all said the difference is too big to ignore. I checked the sound setup, and selected "others" as headset, turned clearaudio+ on.

I do not believe this is how it is with Z2 as the difference is so large and this forum will be full of complaints of this type if that's the case. Does anyone else experience this problem and more importantly does anyone know how to fix this? The sound quality seems to change slightly when I make phone call and hung it up then turn the screen to sleep, but this only has minor effect.

This is a serious issue as listening to music on the go is one of the most important feature and I have invested significant amount of dollars for my headphone (also Sony's)!!! Please help or I have no choice but return the handset.