Reflash latest ColorOS to both A/B slots:

Download firmware from: https://sourceforge.net/projects/oneplus13flashers/files/Oneplus%20Ace%205/Super%20Flashers/

#Reboot phone into fastboot mode with Volume Down + Power
./Super_Flasher_COS.bat
#Reboot into fastbootd mode, choose English
#Do you want full chinese bloat?: [Y,N]?N
#Are you flashing from ColorOS or Want to WIPE DATA?? (y/n)y

Install trebledroid:

download ROM from: https://github.com/TrebleDroid/treble_experimentations/wiki/Generic-System-Image-%28GSI%29-list

flash GSI image into super partition:

#reboot phone into fastboot mode
#reboot into fastbootd mode
fastboot reboot fastboot
#flash system image
fastboot flash system /path/to/image