Damp In The Bedroom

Verb

I live in a terraced house and in both bedrooms I have started getting a spot of damp in the corners only on the window walls.

My loft is well insulated and bordered. Except for near where the windows are due to not being able to reach that far due to 2 large wooden beams that come almost to the floor.

It is an old slate room with no felt. I have had the roof looked at and i'm told that it is all fine and secure with many years left in it.

I have also read that the areas of my loft with less insulation that the rest (By the window walls) is possibly getting damp due to the warm air rising meeting the colder air above it.

Can anyone shed any further advice?????