Did the whole Helix disassembly like
@Alex Kenivel showed in his (2nd) video. Worked like a charm to open and close the thing. So thanks for the that.
But it did not help much. Some of my footswitches are still super unresponsive (TAP, FS2). Mainly the ones I use more than others. Nothing against some wear'n'tear, but I expect more from a 2021 made 1500€/$ (at that time) unit. I think if the Helix ever swims upside down in the fish bowl I'm looking for something else as my Pod HD500 had the same issue some time after using it.