Sounds like you are having lots of frustrating fun and games
Yes my TK 27L Record button is noticeable stronger/harder to push down compared to similar TKs like TK 14, TK23 etc.
I think in my case it is just due to the stronger sprung loaded mechanism of the TK 27, I do not think I have a problem with those sliders, which I cannot easily even see on mine. A difficult area to work on.
David