Just out of curiosity, did you verify that it was decay and not stability?
I remember losing chests because the stability sometimes doesn’t propagate correctly after the server reboots and loads up the database. I also remember having two fountains and having to constantly replace one of them because it kept decaying.
So both causes are definitely plausible and both can be confirmed. In one case, you can see the stability loss in the event log. In the other, you can see the inconsistent decay timer using the repair hammer.
I’m asking mostly out of curiosity, but also because it can help the devs nail the bug.