If you have found a bug in the closed ROM, please report your bugs in the official MEGA65 ROM Issue Report Repository as an Issue. That way it is easier to track problems und reference them with the solutions.
For other parts of the MEGA65 infrastructure, please use the best matching repository in the GitHub MEGA65 Team:
CORE: https://github.com/MEGA65/mega65-core/issues
ROM: https://github.com/MEGA65/mega65-rom-public/issues
Tools:https://github.com/MEGA65/mega65-tools/issues
User Guide: https://github.com/MEGA65/mega65-user-guide/issues
We love to get Pull Requests instead of Issues, which directly fix the problem you found! Become a part of MEGA65 development!