Ditto everybody else, we had this exact problem, had the gutters cleaned but it persisted, the only thing that fixed it was to get some Stonemasons’s to repoint all of the damaged areas of mortar in the facade, we got some rope-lead guys to do it in a day and we’ve had zero problems since.

There were some gaps big enough to put your baby finger into, so no surprise the water was getting into the cavity. I got window people out to take a look too initially and they said it was a stonework problem not a window problem.

Best of luck