Happening on Parachain, probably related to cumulus.
Observed in Moonbeam networks (I haven't checked other parachains), currently based on polkadot 9.8 but this happened at least back to polkadot 9.0

So summary:
This bug initiated last year. Collators were panicking because of "Digest item must match that calculated".
The original bug was in the state cache, reported in #7964 and fixed in #7990

However we found some very infrequent "Digest item must match that calculated" still happening in our community collators.
We have run our company nodes with --state-cache-size 4 for at least 6 month and haven't observed this message so I still suspect there are "rare" use cases where the state cache is broken.

I won't have the time to monitor the database hoping for it to happen again (which seems to be not even once a month per node), so I don't expect this to be fixed soon.

I'll keep this ticket to add more information if I find some.