I've been frustrated by not being able to do recurring events in SquareSpace for a few years now. I finally decided to give up on the SquareSpace events calendar tool and instead embed a calendar from another website. I ended up embedding our business' Google Calendar which doesn't create the most elegant solution, but it is free. There are other sites like Tockify, CalendarWiz, Time.ly, Loxi.io, etc. that have free and paid plans for more elegant solutions.