Thanks for your reply,
I started with uninstalling and reinstalling The Events Calendar Pro. It did not fix anything. I still cannot create a repeating event without the event repeats being corrupted. It also still created a new category (this time named “21”) and assigned the event repeats to it.
I am in the process to trying to backup my page (working with my server administrator to make this happen) and then I will try to update WordPress.
I don’t know what other plugin would be corrupted. I disabled all other plugins and retested and the problem still remains.
Furstrated.