Does anyone know what kind of tradesperson I should contact to detect where this leak is coming from please?

There has been some staining since we moved in in 2019. We had the gutters cleaned last year and facias replaced in January 2022 (unrelated, needed doing anyway). We thought we saw an improvement after the gutter clean but a month ago, we started to see droplets and far more staining.

We had a roofer round recently who checked the attic and window from the inside but couldn’t find anything.

Not sure how old the windows are but the house was built in 1991 and they’ve been changed from wood to PVC

Update 23/11/22

Thanks for your replies!

Here’s a photo of the roof to the left of the window (if you were stood outside the house)

Here’s a photo of the winow (no ladders so cant get up there at the moment)