I think you are correct in thinking that this was the killer. Not only does community have the difference Different Build Types but current builds are different Android version; official is AOSP 13( T) community is a14.
I cannot suggest any way to recover the data except “expert paid for help” where they might probably take the phone apart (??)
To recover the phone I think you will have no choice but to carry out a fresh install Install /e/OS on a Fairphone FP3/3+ - “FP3” including unlocking the phone which will Format data.