Korg SP-280 sticking/stuck keys

Hi I have a Korg piano where a couple of the keys are stuck ( ie: they won’t go down ) which is a little different to some of the more common key sticking issues I have seen / read about.

Can anyone offer any guidance on cause and the possible solutions/fix please?

Thank you very much

TWO keys next to each other - or “couple” of keys (more than two) next to each other - or random keys stuck?
In decades of repairing keyboards I have found many parts underneath keys or wedge between keys - bobby pins (just the other day), guitar picks, paper clips, coins … you name it.
Unless the keyframe has collapsed (possibility) best thing to take out key frame and have a look.