yeah, what usually seesm to happen is that the new board doesn't have the correct settings for whatever screen you have. And with marlin you have to download seperate screen packs to ide before you attempt to flash the bloody firmware and make the bin file.

It's one reason I really dislike marlin, it's just so bloody complicated rto get it to work.
Once it's working it's fine. But otherwise it's a bloody nightmare.

Did you try flashing the old board back to a fresh copy of the firmware you were using ?

Do you have a makerspace in your area ?
I know they're alot more common in the states than they are over here in the uk.
Somewhere like that would be stuffed full of anoracks just begging to fix your printer :-)

But yeah - screens and marlin, definitely not good.

what is the new board ?