Many rows in the "users" table are updated on a regular basis

Per Grafana it appears that something is regularly updating lots (>= 100 000) rows in the "users" table:

This in turn leads to a lot of dead tuples:

We need to find out what this is and make it stop as I fear this may become a serious issue if the number of updated rows increases. I'm putting this on %10.5 because this seems to be pretty serious.