If I remember correctly the V184.108.40.206.QJKEUXM Rom was on it when I bought it.
Here I opened and then put the EU.dev Rom system on it.
I tried the fingerprint reader on this first, but it didn’t go.
After that I tried a lot, but the mem still doesn't work.
Xiaomi Poco F2 Pro M2004J11G
try to downgrade to miui 11 rom, reboot and flash again miui 12 rom using miflash clean all options.