2007 R230 SL350 Roll Bar - Odd?

[crippo2]

Using the centre console switch, the roll bar goes up and down as it should.

However, when going from 'Down' to 'Up', when the Roll Bar reaches what seems to be its maximum mechanical 'Up' position, the motor/pump/whatever which drives this continues to run until I release the centre console switch.

But, when returning from 'Up' to 'Down', once the Roll Bar is fully down, and after a few seconds in that position, the motor/pump/whatever stops, even with the centre console switch still depressed.

There do not appear to be any error messages in the display.

WIS is silent on what is supposed to happen, but does refer to the 'up/down limit switch sending a 0v signal the the roll bar brain when operational limits are reached

I can hear the up/down limit micro switch operating mechanically when moving from up to down.

So before I get out my trusty lump hammer, could some one with a similar car exercise their Roll Bar and let me know if, when at maximum 'up', the motor/pump/whatever should stop even if the interior switch remains depressed (as in pushed, rather than fed up with lockdown!)

thanks in anticipation