I have this exact issue running 25.04.2.5 (well my changed to size is different but same symptom, kernel log spam using the UI)
Nov 4 05:44:24 truenas kernel: loop0: detected capacity change from 0 to 3277304
Nov 4 05:44:24 truenas kernel: loop0: detected capacity change from 0 to 3277304
I updated to 25.10.2 Goldeye and this console spam stopped so I guess it’s fixed.
Aside, 25.10 added update profiles and the only profile options are “developer” or “early adopter”, so I’m no longer on the “general” train.