Hi

After system upgrade (OTA), there is a constant boot loop.
Blackview logo then bootloop.

I tried power button and volume + without success.

How to stop the phone and reboot in normal mode?

The problem is probably related to recovery mode, I installed TWRP through flashify app. No error message but unable to access recovery mode.

Thank you for your help.

sorry, we can not give service for phones with changed third party firmware (TWRP).
I suggest to reflash completly to latest original firmware.