App changed security settings

[Rowb1]

I have an Xperia Z3 compact which is encrypted so I can use Exchange. Recently I noticed the battery was draining quicker than before so decided to install Greenify to manage app usage. I entered my PIN without thinking about it when it prompted for a restart.

On restart my exchange account prompted me to change my device security but when I tapped to do so it just went back to the home screen and notified me again. I tried deleting and reinstalling the Exchange account but the same thing happens. I noticed that now when I restart the phone it doesn't ask me for my PIN, which it should as it is encrypted.

I figured a factory reset might resolve it but then I would lose my 32GB SD card as that is encrypted and apparently won't be recoverable after a reset.

Greenify has obviously done something to my security settings that my exchange account doesn't like. I just want to know, is there a way to undo this that doesn't involve effectively flushing my SD card down the toilet? I'd like to be able to read work emails and keep all my data!

[Phy]

What if you
1. Uninstall that app
2. Restart the phone

[Phy]

if you still experience that, boot on safe mode

How to boot on safe mode
http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008#U348008

How to boot on safe mode on Lolipop
1. press and hold the power key
2. once you get the pop up menu 
3. press and hold "power off" 
4. Boot on safe mode should become available

[Rowb1]

Hi, thanks for your suggestion. Restarting the phone doesn't fix it. Rebooting in safe mode doesn't fix it.

On startup it still loads with the lock symbol indicating that it's encrypted but it doesn't prompt me for my PIN. Something about the security settings is clearly broken now and I don't know how to fix it.

[Rowb1]

I think my only solution is a factory reset but I don't want to lose my SD card. I'm pretty sure I can copy the data off it so I just want to check that it won't be locked and unusable after I reset the phone.