Hi Christopher!
Thanks for reaching out to us! 🙂
A recurring event series will import as non-recurring/separated events whether or not you have The Events Calendar PRO active (the add-on that supports creating recurring events series).
There’s no built in way of importing recurring events as such into the calendar (though it’s a ticketed feature). Options are to import as single events and create the recurrence patter manually (you’ll need Events Calendar PRO for this), or import all instances of the event as single events, just like you are doing at the moment.
I hope that helps! Let me know if you have other questions and I’d be happy to help.
Best,
Victor