Can't connect to Postgres datasource

Hello

Need help on debugging, where is the connection issue regarding connecting to datasources. Datasource types are Postgres.
When I am on datasource page (in UI) and push “Test Datasource” it just hungs. In logs I see:

[2021-09-22 08:58:42 +0000] [1] [CRITICAL] WORKER TIMEOUT (pid:10)
[2021-09-22 08:58:42,195][PID:10][INFO][metrics] method=POST path=/api/data_sources/2/test endpoint=datasourcetestresource status=500 content_type=? content_length=-1 duration=30221.52 query_count=4 query_duration=11.19
[2021-09-22 08:58:42 +0000] [10] [INFO] Worker exiting (pid: 10)
[2021-09-22 08:58:42 +0000] [489] [INFO] Booting worker with pid: 489
[2021-09-22 08:59:12 +0000] [1] [CRITICAL] WORKER TIMEOUT (pid:12)
[2021-09-22 08:59:12,861][PID:12][INFO][metrics] method=POST path=/api/data_sources/2/test endpoint=datasourcetestresource status=500 content_type=? content_length=-1 duration=30619.77 query_count=4 query_duration=9.87
[2021-09-22 08:59:12 +0000] [12] [INFO] Worker exiting (pid: 12)
[2021-09-22 08:59:13 +0000] [609] [INFO] Booting worker with pid: 609

Seems like the worker that tries to connect, gets 500 back and timeouts constantly.

Redash version: 10.0.0-beta.b49597, setup was done in Kubernetes.
But the issue was also with all v9.

I downgraded now to 8.0.2.b37747 and this version can connect to refresh schema but queries still remain running

It seems that although jobs are inserted to redis queue, there isn’t anything to pick them up. They will sit there forever. Is this somehow worker problem or?