Another workaround is to:
– Remove the venue.
– Make changes and Update (which will work)
– Put the venue back in and Update (which should also work)
This appears to be a known issue with The Events Calendar: https://theeventscalendar.com/known-issues/#tec-4596
Options: Downgrade the Events plugin, downgrade WordPress, or use the hack of removing the location before updating (then putting it back)
