That’s what I did. Please note:
- I got plenty of “_2” entities (the former shadow entities), without having the “normal” ones. So I renamed those “_2” entities, e. g. “sensor.cpu_clock_2” now is “sensor.cpu_clock”. I think that might be the actual reason. Root issue: why there were only the “_2” entities after adding unique_id’s and reloading the sensors.
- I think another “logical miracle” additionally kicked in here: HA was running for longer (18 days) than the recorder “purge_keep_days” setting (14 days) which is why there were no states for many entities (because of a lack of entity value updates during the last 14 days).
Pretty complicated, don’t think I can get the history back (without needing to fiddle around directly in the database which is what I hate and for that reason there’s Fix Individual Entity Data Points and similar).
Lesson learned (the hard way, by loosing plenty of history): always add a unique_id right from the beginning when creating a new sensor. Saves tons of time…