Thanks for pointing that out! It seems to be a flaw in the recently added “Rich Text Editor” mode that combines the markdown and the preview into a single WYSIWYG editor. It was impossible for me to set the link correctly until I reverted to the old split view editor.
This was also causing problems for the recurring event dates. The “Rich Text Editor” mode was erasing the recurrence, so those dates weren’t being updated correctly. Now everything should be working correctly, but do point out if there are any more issues.