xiaomi pro 2 error 21 after flashing to stock

[terahhh_]

im new to escooters in general,
my partner uses hers for work purposes.
i got her a pro 2 was fine she drove it in the rain.
then got stuck on drive mode, so me doing a bit of research came across the flashing process so i flashed the scooter to then get a new dashboard so she could cyle modes and able to turn it off. i then reflashed to normal speeds etc. but now error 21 comes on only when she turns left for some reason? confused so i read about disabling the BMS is this something to do or am i overthinking the fix for error 21