No events on dashboard

A couple of weeks ago I installed Sentry 20.8.0 via docker compose. The only change I had made is the nginx port change. Further, errors in the sentry were sent by another department.
A couple of days ago, 2 problems appeared,

the first OOM was killing processes, we added memory to the server up to 16 GB (specifically, it killed redis).
new errors sent to Sentry, but no displayed in the web interface.
Next, we decided to upgrade to version 20.9.0 and add the line postprocess.use-cache-key: 1.0.

But as a result, the problem with displaying data in the web interface persists. I tried to figure out what could be wrong. and while I got the impression that redis is only growing since the size is not reduced (although it probably depends on the data flow). Those. I couldn’t even send the python script test error.
I understand that the matter is most likely in some kind of worker, but I do not understand why it suddenly broke and does not work on the updated installation.

docker logs -f sentry_onpremise_worker_1

11:19:43 [ERROR] process.failed.empty (cache_key=u’e:9f79909dc81a49e6ab81c1013c8576c3:2’)
11:19:43 [ERROR] process.failed.empty (cache_key=u’e:5bcea6b6d85d4ca3b4e9010f9fcdae33:2’)
11:19:43 [ERROR] process.failed.empty (cache_key=u’e:606f6377a64749a78effed582ba37707:2’)