flashing tape

Hi, our house built 8 years ago has dry ridge roof system and the metal foil tape/aluminium flashing has lifted up. The tiles are still in place. Asked the builder and they said it’s out of warranty, asked NhBc and they said if it’s not leaking they don’t want to know. Not sure if it is a...

So, we've been having leaks for nearly 18 months on our garden office, which has velux-equivalent windows on a flat roof, when they're meant to be on an angle of 18 degrees (I think?). While we wait for the builders to come up with a meaningful and final solution, I want to flash-tape the...