Maximum trading quantity for Oil Futures is 0?

Why the maximum trading quantity for Oil Futures expiring on 19 of May is 0?

Because it’s expiring. Go to the next crude oil contract.

It’s expiring, but not expired, so should be tradable. In fact you still can trade up to 0.9 contracts.

Apparently now you can sell as much as you want, but buying is still limited to 0.9. July’s is limited to 250. Is it some kind of protection because of the last month’s negative prices?

I actually experimented the same thing for the first time yday… i tought that expiring day was yday but i was wrong so i sold too early and wanted to buy again to make some more profit before the expiring but it was saying i could not buy anymore… i tought the same thing (about expiring limitation) but if you saying that even for the july one there is a limit… then its a quantity limit for that instrument, could be covid-19 thingy or website limitation… there isn’t anything that say that