About chess.com's post game analysis and best moves

You know how at the end of every game there is the option to computer analyse your games, and all the best moves are shown in green and inaccuracies blue, mistakes orange and blunders red.

Now in this game on move 37. Kh2 is the ONLY move. However when I put the game in analysis it doesn't show Kh2 in green, which means its not the best move. So is there another alternative that I fail to spot? Obviously not.

So why isn't the only move in the position showing up on analysis as the best move and hence in green. I checked twice and yet it doesn't show up as green.

No explanations?

I would say you assumption here is incorrect. If white has only one possible move, the engine has nothing to compare it to. It cannot make an assessment whether the move in question is "best".