Originally posted by fusioncut:

I have had celebrations for finally getting the top of my building to stay up, gone afk, come back and sit down for awhile to decide what to add next... an hour after I finished... one falls... then another... right back to where it started before I "fixed" my support issue... Just takes one... very frustrating... heh

To be fair, there are a lot of support calculations that need to be done for a larger build, and the calculation seems to be rate-limited, too. The larger the build, the more pieces it has to check; even "small-ish" builds can take several seconds before the engine figures out that a particular roof piece (for example) isn't actually supported, and collapses it.

It's theoretically possible that some of these much-delayed collapses are simply due to having to check literally thousands of connected pieces before determining that "this particular piece" isn't supported well enough.

That being said, chunk boundaries are also an obvious potential culprit. I hope we get to the bottom of it soon.