Have a look at the sealing credibility of the rubber between the screen and the scuttle. On my car there is a slight mismatch in the curvature and the outer rubber is not tight down onto the scuttle in the mid section. It is ok towards the outer areas. When I looked under this rubber I spotted the electric screen demister wire poking through as well. This meant the inner rubber was not sealing to the scuttle either. I teased the wires back under this inner seal and used a mastic to put a bead under the outer rubber to butt up to the inner rubber.
This is a consequence of the hand made nature of the panels giving rise to small variations which mismatches other parts.
In this case a relatively simple fix just by using mastic. A bit fiddly as keeping a continuous bead is needed but not too bad.
Captain Tolley’s is worth a go elsewhere.
Check the seals under your wipers and washer jets too. Wipers easy to do but washers need the dash off for access.
