The issue still persists also on my side. I’m facing it in the Google AI Studio Playground, and even when I use simple short prompts it’s always returning the same “an internal error has occurred” error. And the support is really bad, I have never got any response when reporting bugs. If you’re still facing the issue, like me, you might want to also follow the topic right here: Nano Banana Pro: An internal error has occurred
People are reporting the same bug there as well. If it would be solved, you might get the solution on that topic first.