Hi @Donald Sangster
Welcome to our forum!
I can no longer edit the calendar, it refuses to save items. Oddly, it will update if edited via Google Calendar.
It seems to be a known issue, please wait for it to be fixed. Here's a temporary workaround, please refer to: Can't save new events neither edit my calendar - Microsoft Community
It seems to no longer access "sent items". I can find them in Gmail but no longer in Outlook.
To further confirm if the issue is more related to Outlook desktop client, if possible, please log in to your web mail and do the same test to check if the issue persists.
If not, it is a good idea to try removing and re-adding your Gmail account in New Outlook. This can refresh the connection and resolve sync issues.
Hope it helps.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our [documentation] to enable e-mail notifications if you want to receive the related email notification for this thread.