Its been a while since ive posted, my beloved XS8 is gettin old too, ive been replacing keys that arent broken, they just develop a poor feel,,,,, sticky one second then freed-up the next!!! touch is unpredictable, it’s messing up my arpeggios/timing,,,ive had this happen about 8-10 times on different keys over the years, {its definitly not debris or a spill or need of grease} something is wearing out or needs adjusting,,,,,,its expensive to keep replacing them when the’re really not broken, the new keys always work out though, i just dont get it! any thought’s?

Since replacement cost is apparently an issue, try this…

For black keys, grab between thumb and forefinger, and move side-to-side a bit several times.

For white keys, use one hand to depress the keys to either side of the troublesome one, then “exercise” the key as for the black ones.

That might loosen things up, at least for a while.