Official(?) gTLD Drop Cycle Diagram [icann.org]. YMMV
Domain expirations can lead funny lives.
For instance, there was once someone who figured out that IF they renewed a non-owned domain (you used to be able to do this) with a stolen credit card THEN the domain registration would show that the domain had been renewed - and whoever held the pre-drop drop-catch order would release it - AND THEN the scam artist would place the (exclusive) drop-catch order - AND THEN, when the renewing-registrar realized the credit card payment was fraudulent THEN they would drop the domain . . and guess what scam artist genius would snag the domain?.
How do you like them apples?
How did those of us affected by this process figure this out? By a bit of pattern analysis amongst friendly competitors. No doubt, whatsoever, about the pattern analysis. We all saw the same BS, for awhile, with scam renewals - BUT we didn't release our catch orders - and ended up with the domains. Frackin' thieving, slimeball, evil con job SOBs . . . Just gotta not fall for their tricks. ;)
Almost as bad as an insider at a major drop catching-auction compan bidding on domains auctioned by his employer/company.
So, you ask "What's up with this domain dropping?" All I can tell you is IF you REALLY want it then place your bets everywhere you can, especially if it doesn't cost you any money to place the order.
And leave nothing to trust, not even your bidding if you get to that point.