Mac Mini 2020 Display settings resetting on LG TV

I have a Mac Mini (2020) connected up to an LG TV via HDMI. I've configured the Display settings to have the Mac screen fit perfectly on the TV screen. However, whenever I reboot the Mac the Display settings seem to be reset, until I go into the Display Settings window and click on the Underscan slider. It then corrects itself. This is quite annoying to have to do this every time I reboot (it works fine if just using Sleep). I've tried ensuring the aspect ratio on the TV is set as 16:9 rather than 'Automatic', as found on another forum this was a suggested solution (it didn't work).

Has anyone experienced something similar?