One Move Blunders

I'm sure this is a common question and I feel like the answer I've seen most is "play more," but I want to find out if there's a particular kind of drill or exercise to help with this exact problem.

The problem is that I'll play decently, up until about move 20. Somewhere it the 20's I always seem to make an absolutely stupid, garbage, awful, game-ending move. It's not a miscalculation or an unseen tactic, it's just putting a piece on a square where it can be taken for free. The dumbest possible move in many cases.

I don't understand why my brain does this. It just decides spontaneously to be blind to obvious threats. Often I regret the move instantly after playing it. Even if I spend a good chunk of time thinking beforehand, the obvious badness of the move just escapes me until I play it.

I feel like this problem is hindering my chess progress. It's not even worth analyzing my games since it's so dang obvious. How do I combat this weird, momentary blindness?

The video helped me a lot to reduce one move stupid blunders. Of course ‘play more’ is one of the solutions but the ‘keep your stuff defended or if you don’t have a mental note’ is useful too. But maybe I saw the video at the moment I was ready for it. In my long games the one move blunders have almost disappeared (same goes for my opponents btw).
Good luck. I think reducing those blunders are the most important issue before stepping to 1200.

Great video and might be exactly what I need. I've been doing the concepts he talks about intuitively, but having them defined gives a sort of "check list" I can do to double check a move.
Still, my issue seems to be when my brain simply stops thinking correctly for a move. It feels like a focus issue, or some weird quirk of cognition.
I guess I'm trying to think of how I can force my brain to play properly all the time and avoid "brain farts."

Hola, alguien para jugar?