That makes sense. I have beaten the first level (3 times now) and even with a reset of level 2 and also entering a code it wouldn’t continue. So the ram issue is logical.
Ill probably just use my Stella CD in combination with my Supercharger (once it arrives), I was hoping to use a flash cart for a faster way to play these games but that seems a bit out of my ability. I am impressed you found a functional rom though.
If you have a version that works please send me the file. I’ve tried my Stella Gets a New Brain combination version, and 3 different versions I downloaded and none worked beyond the first level which is sad.