Hey Ethem, could you test with only heatmap enabled? currently the macOS (Qt6) is fine but it might because I just filled in some days to test this issue
if the issue don’t go away, then downgrading is an option, make sure you downgrade properly
After using the latest version, if you wish to open your collection with an earlier Anki release, please go to the File>Switch Profile menu item, and click on “Downgrade & Quit”. If you skip this step, you may get an error message when opening your collection in an older Anki version, and you will need to return to this version, downgrade, then try again.
You likely still have an old version of the add-on installed that’s not compatible with newer Ankis. Head to Tools → Add-ons and uninstall the one that’s listed there, then reinstall Review Heatmap from AnkiWeb.