Owned our 95 troll for 5 years, suddenly the roof needs 2 people to close it. When I try on my own, I close one end, then when closing the other end, the first end pops back up - multiple times. I have the door open and start with the front end, just can’t think what the issue could be?

The mechanism may have seized and the frame is bending rather than moving? Or it has become too loose and the spring just pushes it back up again as there's little resistance? Has it been lubricated recently? Try posting a photo of the mechanism through the triangle aperture so we can see what it looks like.

Hope you sort it,
Simon

Have you got some item resting/stuck on top of the bathroom/wardrobe making the roof act like a see saw?.
Or
Is the roof bowed?
Steve

we had something trapped under the bathroom mirror once, that stopped the roof from closing and it acted in a seesaw manner.

check bathroom mirror.