Volume of a strike was just 1. Is it possible to inspect from which market participant (ie. the four-letter ID of the MM or brokerage firm etc.) this order came in? More info: order was placed pre-market, orderbook had Bid and Ask. I took the Bid for my ShortSelling order (actually a CoveredCall, ie. a NetDebit order). IMO it had to get filled as everything was exactly calculated. The new LastPrice is my own offer. Ie. someone else got the fill... More more info: https://www.investopedia.com/terms/f/frontrunning.asp
More details? You know there are 16 option exchanges and even if you are first at a price, they can match it on another exchange. Or, step up in prices a pay a little more. Neither are a violation.
Option order books do not show option data in Realtime before the stocks open at 9:30am and then have an opening rotation. The rest of your comment I did not follow. If order to buy stock and sell a call on the exchange COB, someone needs to want to trade with you at that price.
I don't think TDA sends such CCs out to the exchange COB, but handles it rather internally/locally in-house. Both stock price and option premium were matching for a fill.
ALL option orders get executed on an option exchange by the DMM they route their orders to. Pre market prices as left over from the previous day. They are not live.