Massive movement on flat roof membrane lifting in wind.
This roof is a dorma conversion up in the loft space.
Had a new flat roof before I bought it but I've been told before it started lifting that it was placed on top of the old membrane.
Video of movement here.
https://www.youtube.com/watch?v=Gck8Ctktp0Q Sorry its upside down
How do I solve this issue, and why had it likely happened?
Does the sheet need to be lifted put back down and some weight added too it?