Agreed, as you have Fairphone4 imo downgrading is unwise.
Please let us know if you can make any progress with @rezoe’s suggestion.
I added fp4 to the tags on your thread; in case a Fairphone angel can offer any help, you might also let us know if you are running a stable or dev build. A Murena purchased phone or one installed with Easy Installer will be on stable.
- [HOWTO] Give complete /e/OS version info easily for support, answers, comparison etc (ofc might not be possible in your position)