Decay transitions do not work on objects that were tapped out.

[TwistedHBG]

If a tapout transition is triggered on object A by a different object, decay transitions for object A will NOT work. This can be easily tested and reproduced by using property fences - renewing a horizontal or vertical property fence also automatically renews adjacent corner fences. Those corner fences will never decay and they will remain in their renewed state forever.

Here's a video example of me renewing two corner fences by using the tapout, and two corner fences by renewing them directly (just skip to the end no need to watch the middle, it's there just to be proof of the bug) - https://youtu.be/Ah7UKvQTGMI

The ones renewed directly decay properly after 3 minutes, while the ones repaired via tapout remain renewed forever.

Here's an image of me standing in the same spot over 30 minutes later - the tapped out fences are still renewed.

Removing the middle two vertical fences which auto-orients the corner fences into horizontal fences doesn't seem to let them decay either

But I'm sure that there is some sort of way to make tapped out objects decay properly, because otherwise dead towns would always have permanent renewed corner fences, and they don't. Perhaps they decay in 3 hours rather than 3 minutes? I do not know.