Disappearing Chests - decay bug?

Game mode: Online Official PvP
Problem: Bug
Region: EU 1100

On two occasions a few chests have disappeared. It seems they have simply decayed. I’m looking at many chests atm, and their decay time does not fill up. I relogged, and they started at 144 hours again, but not filling up.

I also believe that the chests that disappeared was not opened for many days - but they were in range of clan member every day for many hours.