Flying from US to India. F1 stamp is not expired but visa changed to H1B- going for stamping. Will I require transit visa in Schengen Area?

Question

my F1 stamp is expiring in 2027 however I was picked for H1B this October and am going to India from the US for H1B stamping. I am concerned if I will be able to transit through the Schengen area without a transit visa. Can anyone help? I am looking at flights with layovers in London, Paris, Munich, and Frankfurt