I intended to travel from US to Greece via Switzerland (airport only), but I just noticed that my EU member state passport is expiring shortly after my return flight date (i.e., it does not clear the 3 months rule).
I also have a US passport with no validity issues and the trip would be shorter than 90 days.
I tried to Google this but most resources are unclear on which rules apply to non-EU citizens vs EU citizens and travel within Schengen vs entering Schengen.
Would it be OK for me to use my EU passport or should I use my US passport instead?