I have a problem with currencies, default currency is euros but on checkout when I change address to a country without currency specified, it shows Swiss Francs.
Swiss francs is the last currency that I have as to be shown in all countries. It looks like when you select a country without currency, goes through the whole list of available currencies and displays the last option instead of the default currency.
1. Clarification
You wrote: "... Swiss francs is the last currency that I have as to be shown in all countries..."
Do you mean that this was the "most recent currency" that was added? or do you mean something else?
2. Sandbox site
Could you simplify the case to have only 2 currencies active. Please wriite back with specific steps to replicate the issue in this case.
1) Exactly, when you change to a non european country, it changes the price to swiss francs (most recent currency added) instead of euros which is the default currency
2) Done, I disabled all plugins and childtheme and left only 2 currencies.
In this case the steps are very simple, changing billing/shipping country at checkout, currency displayed is euros in european countries, which is correct but swiss francs in the rest of countries, which is not.