It might just be clumsy me, but this only works on the emulator.
Couldn't get it to run on the real hardware.
Viewing post in Mega Sisters (Mega 65) comments
Did you update the ROM files/Cores? AFAIR there were some incompatibilities introduced later on; and there was a time, when it really wouldn’t run on hardware. I can assure you it does run generally, but as the Mega65 is a bit of a moving target there are occasions when it doesn’t. I’m currently not in reach of my Mega65, but I’ll check to make sure.
Thanks, I tried several different combinations of core and kernal rom. Currently on the core dated 23.06.22 with kernal rom 920377. Maybe I'll have to go back a few versions but then other stuff won't work again. Yes you are right the M65 is a moving target atm and once they fix one thing two others become broken. That might just be the case here too.