I used the method described by Rwmega (by thanks to you !) here https://forum.xda-developers.com/sho...&postcount=287
and flashed a slightly altered 2019060619 S3 Pro ROM with the boot.img of the 2019043022 this morning.
No more generalized touch screen freezing. I can use my phone again.
Unfortunately, my touch screen problem is not 100% solved !
The upper half of my screen regularly becomes totally unresponsive when I do not hold the phone in my hand and only touch it with one finger (when the phone is on my desk, for example). It never happened before.
I am not the only one with this problem :
Here is a post from an Indiegogo backer describing the process that will enable you to check if your S3 Pro is now affected by the touch screen issue caused by the latest update on some devices :
The conditions under which the sensitivity of the touch screen on the 20190705-1722 Update decreases.
- Attach the S3 Pro to a tripod or selfie stick and operate the touch screen with one finger.
- At this time, make sure that other fingers and hands do not touch the S3 Pro side and back. (If you hold it in your hand or operate it with two or more fingers, you will not see any symptoms.)
We are in trouble because we attach S3 Pro to tripod and use.
Please correct it immediately.
You do not need to use a selfie stick in the first step. Just remove the phone from its protective case (if any) and put it on a table or a flat surface. Then, touch the screen with a single finger (try with the upper half of your screen).
I am able to reproduce the touch screen issues with a success rate (I would rather call it a failure lol) of 100% when I realize the conditions described in this procedure.
One could think that the latest update revealed a touch screen grounding issue on some devices, that was previously compensated in a way that affected negatively a good chunk of the S3 Pro userbase with touschscreen freezing issues.
Now that they fixed it, a few people like me are f*cked : they just transfered the problem to another subset of the S3 Pro userbase.
PS : Obviously, no answer from Umidigi...
EDIT : testimony of another victim of this update found in the Indiegogo S3 Pro page comments section :
guys do not updae. screen touch is very bad now. you have to press hard and also it dosent register some touch. its vwry annoying. Do not update.