Hi Phil,
Due to your unstable scenario about access to team site and visit libraries, would you like to provide you domain name for me so that I can help you check the issue on my environment? I have sent you a private message to protect your privacy. You may respond with the requirement information.
To see the private message:
1. Please go to the Your details section on the right side of the community site.
2. Click Private messages.
3. Click the subject title of the response to read the message.
In addition, have you tried any special steps to fix the issue during experience the temporary issuing situation? It is very important to find the root cause and troubleshoot the issue if you can post further information and screenshots here.
Thanks,
Maggie Li