I have been using Lightning in Thunderbird for several years. Up until a week ago, it was syncing with my Google calendar. But now, events that I create in Google are not syncing to Lightning. In fact, I cannot even create events in Lightning now. The newly Google-created events are syncing with the calendar on my Android phone.
I do have the Google provider extension installed and Lightning is the most recent version.
Provider for Google Calendar 3.1