Url event is in greeks

hello I have a problem in our events when I ckick the event that we have in greeks translations it goes to mydomain/γεγονο?/my-event-title

this is no correct for ulrs so the page is not display

how could I change so no to have “γεγονο?” but event?

I would also like to ask how can I hide the layout buttons?

thank you