Edit: I was told that it was on timer, but the amount left shouldn’t really be shown.
The bug that is happening is the 10000 have not sold out at 101 robux, but you can only buy the ones being sold by others.
Is this the first time they’ve had a Limited U with a timer? I don’t think this bug really affects anything much, just the number on the item page.
There was one before, which was the peach thug shades, which was about 6 months, about 33 sold or 50. There is a good chance this is not the case.
A timer shouldn’t have caused it, as Hooded Firelord, Rbadam’s smoking top hat and other hats have had to been put on a timer in order for the original buyers to sell and trade it.