ENGINE BUG

I was playing the Computer when Chess.com was temporarily down for updates few hours back..

I was losing but I was not mated but computer engine kept saying it is mate but it was not mate!!
Here are few examples

In all the cases my king is not mated

also I have a question:-

what was chess.com down for few hours back? which updates took place?

It doesn't seem to say that it is mate in any of those screenshots above?

in the engine evaluation box, see, it is written checkmate

Yes that is usually how the game ended. In checkmate. Probably on move 46 or 47. Those three screenshots are from the same 1 game - unless you played the same moves in the exact 3 games? Look at the notation on 45...Rb3+ just has you in check. Not checkmate

So in the 1st example you have 38...Qh1 highlighted, That is not checkmate and the computer did not state that move was checkmate. Also you made moves after that which would be impossible if it were checkmate. In the 2nd example you have 43...f4 highlighted which is also not mate and the computer doesn't say that is mate, if it did say it was mate then you wouldn't have been able to play 44.exf4 and continue with the game. In your final example you have 45...Rb3+ highlighted. This again is not mate but after 46.Ka1 or Ka2 we have 46...Qb1# which is forced and how your game ended. Hope that clears it up for you.

He means this:

in each case you had mate on the move, but didn't make the move.