You're using Rover-3.2.0-rc4? This is definitely the version to use as it's very close to being released.
In Rover-3.2 we've separated the input and output configurations. In the past RC1_REVERSED might have reversed both input and output (I'm not sure) but now RC1_REVERSED only reverses input. SERVO1_REVERSED can be used to reverse the output so perhaps this is what you might need to change now.
The issue could also be in the turn rate tuning or navigation tuning but I'd need to see a .bin log to look into it much more.
Thanks for using ArduPilot!