I have yet to find a reliable set of reproduction steps, however I have noticed that some object dimensions can randomly change. For example, imagine you are making a cylinder that will fit around a camping propane tank. The top of said cylinder is open, with the bottom being closed, so a vase like object. Centered in the bottom, is an additional negative cylinder 38mm in diameter and 4mm deep, creating a recess for a magnet. I printed it out on my 3d printer, and the magnet size was perfect. It fit. Unfortunately, I needed to remodel it to make an a minor height change. I simply hit ungroup, which ungrouped my magnet recess, made my change, and regrouped the magnet recess. 8 hours later, the print has progressed far enough to observe the now tiny magnet hole. Back in tinkercad wonder what is going on, I norice that my magnet recess negative cylinder defaulted itself back to 20mm. After some google searching, I found a reddit post of the same issue from three years ago... Is this a known bug with no intent to fix? Or is it an issue of, no one can reliably and repeatedly reproduce in order to fix? I was absolutely loving tinkercad for quick things, but when prints take days, it doesn't make much sense to roll the dice on if what you modeled is what was actually exported from tinkercad. Any ideas? I can ungroup and regeoup a 100 times and not reproduce. But I can open models from a month ago and 1 in 10 have the problem it seems.