Valve Cover Leak Only After Winter Storage?

[Ximian]

My car is stored in an unheated garage from about October until April. The first few times I start the car, I see an oil puddle mixed with moisture under the back right (passenger) side of the engine. The leak only happens when running. After it warms up later on in April, no significant leaks. This has happened every year since I bought the car in 2016 and I attributed it to a leaky valve cover gasket.

I replaced the VCG last summer and had no leaks at all until I started driving the car last week with the leaks back. I used BMW gaskets and new bolts so that should be in good shape. The idea that popped into my mind is that corner of the valve cover must be warped/bent from damage due to a previous owners VCG job. When I did the gaskets last year, I didn't notice any damage or bending but I didn't closely check for it either.

Anyone else have a similar issue with new gaskets after winter storage? Would like some feedback before I buy a new valve cover.

[Ximian]

Adding a video from 2021. Looks like condensation from the headers and other things warming up combined with some oil. Hasn't occurred again for me since the first two starts earlier in the month and it's been slightly below freezing on the evenings.