If your phone is stuck in a boot loop, you cannot access the settings menu, or you want to downgrade your Android version, you will need to "flash" the stock firmware manually. This is an advanced procedure.
The Ultimate Guide to TCL 20E Firmware: Updates, Flashing, and Troubleshooting Firmware TCL 20E
After the device reboots, you can verify the current version: About phone System Update If your phone is stuck in a boot
If your TCL 20E was linked to a Google account prior to flashing, Google's Factory Reset Protection (FRP) will trigger upon rebooting. You must log in using the exact Google username and password previously configured on the device to access the home screen. Ensure you have these credentials handy before performing the flash procedure. You must log in using the exact Google
: Ensure your phone has at least 50% battery capacity to prevent it from shutting down mid-process.
Maintain a minimum battery level of 30% to 50% . A sudden power loss during writing blocks will permanently brick the device hardware.
: Resolution for common software glitches or performance lags.