I have compiled a short article on fixing LEGO switches that don't want to switch over to siding, and on possible replacement for the switch spring if this turns out to be the culprit.

Full story here: https://www.biasedlogic.com/index.php/fixing-lego-railroad-switches/

Hope you will find it useful.

Happy 2021,

M.

Interesting endeavor and a handy tip to keep in mind (wrt the compressed air)