Originally Posted by askwong
After factory reset my beloved C6806 (Sony Xperia Z Ultra ) and unlocking the bootloader through the Sony official unlocking procedure, I found my Facebook, Gmail, SMS and more apps started failing to run. Especially Facebook app, it just worked once after fresh installation. After restarting the phone, the Facebook app was no longer work. The screen kept flashing several times and then exited. I was never able to make it work again.
The only way to reviving the Facebook app was through clearing data in the app (Settings>Apps>Facebook>Clear Data). However, It required login to Facebook again then worked until the phone restarting. The same symptom repeats again, again and again. I am so frustrated because the problem of instability then extended to more apps. I had also tried to install Messenger or old version of Facebook App but there was no luck at all to solve the problem. The phone started running unstable.
I originally planned to install a custom ROM and root the phone in order to resolve the problems. In that moment, I had an idea and guessed that the problems might be caused by the bootloader. The I use Flashtool and lock the bootloader.
Wow La .................. All the problems are solved and no more problem existed.
If you have the same problem with Sony smartphone and the phone is bootloader unlocked, please try to relock the bootloader again. It may solve most of your problems.
Additional note: Some people have mentioned the problem of Xperia For Facebook. This is the hint for me to think about the source of problem coming from the bootloader. Sony's default apps have a habit to check the bootloader status of the phone before running like FOTA Update. No more update is avail for those unlocked bootloader Xperia smartphones. So do not use Official ROMs if you want to unlock bootloader. (However, many apps will stop running with custom ROMs like bank apps or Google Pay.) Please install custom ROMs with unlocked bootloader Xperia smartphone. Do not keep using the Official Version ROMs because this will be your beginning of nightmare.
........calm down. You can't base your conclusion on that vague investigation.
Stock rom is so old and abandoned sony haven't added anything new to it like blocking facebook.
Yes some app developers are starting to block access to rooted devices is different ways.
There is no signs that facebook ie microsoft is blocking rooted devices yet.
But recently google is implementing only a simple block so you cant download the app from play store. But you can simply install the apk manually.
You should try something else first. Like flashing a stock rom ftf. Wiping the whole phone after the unlock including internal storage and sdcards. Even if unlocking wipes the phone.