First things first, before suggesing a solution to this, know that I have a laptop.
Sometimes in Garry's Mod, I will be typing and I can't backspace. Also(including the backspace problem), every time I press the H key everything dissappears.
Let's say I want to say "I have it".
Say:I _ --> Say:a
The only solution to this for me is to restart GMOD. I would appreciate it if anyone can tell me how to fix it or what causes this. Thank you.
UPDATE:I pressed the cleanup button and it happened again. That might be the cause. This time, it happened with the key S. H was fine.

I didn't press the cleanup button and it happened again. PLEASE HELP ME SOLVE IT I AM SO PISSED! IT JUST MADE ME ACCIDENTLY EMPTY A REALLY IMPORTANT PROP FOLDER!

I get this sometimees, i dont know what I do, but sometiems im typing and it cleans up everything. Very annoying!

No clue

I have no idea if your issue is this, but I sometimes get that a program will stick a key, like TF2. So if I'm alt-tabbing, it will stick my ALT key on, or sometimes my shift key. Where minimizing the game, then pressing sticky button, then maximizing again will help.
I don't think it's the same you have encountered though.

Nope.