GLC Coupe - rain leak

[Lolly9416]

I’ve noticed with the heavy rains that the passenger side footwell in my GLC Coupe is getting wet. And we just can’t figure out how it’s coming in.
Has anybody else got this issue?

It’s not coming from the front but the seals on the door and the door itself is not wet. 🤷🏼‍♀️

[trevalvole]

Some non-specific thoughts:

A drain for something like a sunroof etc?

Leaves blocking a drain under the bonnet by the firewall and cabin air filter?