W124 sunroof motors in winter

[ktlimq]

In winter, my sunroof does not operate for a while after I start the engine.

When the inside of the car gets warm, then the sunroof operates normally.

Once it operates, I let the sunroof open a while to let the moisture evaporate.

However, I get the same problem next time: sunroof does not operate first, when the car gets warm, it works.

Is this usual? Or does this indicate that there is water leakage through the old and rust repaird (with POR-15 by myself) sunroof seal?

If so shall I remove the rubber seal (picture below), smooth the rust area, then put a new rubber seal?
(in W124, the rubber seal is attached to the roof, not the moving panel)