Using rclone cache with unionfs?

1.40 stable has the bug of updates not getting propogated to the cache. The fix is in the new beta just rolled out this morning and t in my initial testing this morning looks to be working much better. You can read some on it in Cache polling not working and Google Drive change polling and cache invalidation.

So yes if you want to remove the behavior you are seeing you will either need to move to beta or wait for the next stable release. .