All Calendar resources not syncing
Google Calendar resources
The email used to authenticate your calendar resources needs to be a high enough admin level to grant Read and Write permissions to Envoy.
If the permissions are correct but Envoy is still not syncing Rooms, it's possible that your Trusted API setting is turned off. You'll need to grant Envoy access to Google's API. Here's a Google guide on how adjust this setting.
Outlook Calendar resources
If you have a hybrid O365/On-Prem environment rooms will not sync over.
You'll need to be authenticating with a super/global admin email who has the ability to allow Envoy read and write permissions on your room resources.
Some calendar resources syncing
This is likely due to the email used to authenticate your calendar resources not being an admin on every room you are trying to sync.
Log into https://admin.google.com/ and go to https://calendar.google.com/calendar/. Click the Settings button. Go to the calendar for the failed room and share the calendar with the connected account.
Go to your Azure portal, find Enterprise applications and navigate to Rooms, click into it and look at "permissions". The permissions given should match the following.
Book now and End meeting not saving on the display
With both Outlook and GSuite you might click "Book now" or "End meeting" and it will work for about a minute and then revert back. This means that this calendar has no write permissions given to Envoy.
To give write access to envoy for your room resources you'll need to edit the settings of the specific calendar.
How to report a problem on the iPad
If you're noticing an issue with the iPad paired to your room (calendar not updating, pairing screen not working, etc.) you'll want to triple tap the iPad screen and then fill out the email with as much detail as possible so we can get a good grasp of the problem.