I've got the same problem with the "My hands" button.
The "Loading..." status is displayed on the "hands list" very long time.
Judging the log The SQL Query thread running too long.
When I use the checkbox "Show Marker Hands Only" query has finished in 23 ms. Otherwise
2021/11/09 17:08:06.285 [00101]: [00001084][PostgresConnection (Error)] Warning: Unable to execute query: Fatal Error; Reason: Warning: (ERROR: canceling statement due to user request )
2021/11/09 17:08:06.285 [00000]: [00001084][Query] Query execution time: 61181.20206412 ms
OR
2021/11/09 17:13:22.244 [00277]: [00001084][PostgresConnection (Error)] Warning: Unable to execute query: Fatal Error; Reason: Warning: (ERROR: canceling statement due to user request )
2021/11/09 17:13:22.244 [00000]: [00001084][Query] Query execution time: 215215.67204452 ms
My database is huge = 36 GB. I use hands import from HHMailer so my database is growing very fast.
What I can do with this issue.