Wooden window water leak in a very odd place!

I have wooden window frames which hold double glazed units. In my lounge I have a bay window setup. In the recent downpour I have an oddly positioned water leak into the house.

The water is coming in through the corner join at the very top right hand corner of the right hand side of the bay window. The frame is recessed by about an inch from the outside face of the building, so that the top of the windows doesn't get wet! Yet this is where the water appears to be coming from. Frames are in good condition. They were painted about a year ago outside with quality wood stain type product.

Any ideas what is going on? I can't see any obvious crack or mark to suggest where the water is getting in on the outside of the windows.

Thinking about getting the insides of the window frames painted too, would this cause a problem as I'd use the same stuff as the outside or very similar.

Ta

Andy

whats immediately above!!!!

water can enter cavities runs down the brick and lands on whatever closes the cavity and leak out