It does happen.
Still no resolution. I’ve done extensive legwork from my end including identifying, testing, and supplying video of the fact that you can get back coffers opened in the sanctum, calculating my character’s total exp, plots, cosmetics, etc… There are still a few thousand cubits not accounted for.
I’ve also been told that there is no transaction log or record of cubit purchases - which is one thing for an earned currency but something else entirely for a premium purchased currency.
Anyways, it does happen and not all cases are as cut and dry as checking the DB log for failed transactions, which has apparently been enough to recover lost cubits for a couple of cases.
You can’t actually do this until you’ve leveled again without calculating it yourself based on exp per level since your current level isn’t displayed anywhere. I was trying to capture ‘before’ and ‘during’ screenshots of chest collection for a while but since the number of level chests isn’t displayed anywhere there’s not any actual use for the data in those pics.
If @Marcello666 's cubits were lost due to database errors during recording a ton of chests opened with collect all, there’s a good chance it can be resolved quickly. Especially since it’s recent and he has an approximate time stamp. But not all cases are.