If multiple Gmail accounts are syncing with delays, it is probably because your pub/sub is expired / not working or you don't have a pub/sub setup.
Follow these guides to setup/fix the pub/sub for your Google application.
Please ensure to only use the GSuit app that is integrated with your Nylas application. Pub/Sub setup in any other GSuit app will not work.
- Automated way to create or fix existing pub/sub - Nylas maintains this script that you can run to automatically provision the GCP resources in Golang.
- Manual setup - Follow this step-by-step guide to set up pub/sub manually. This can also be used to verify and fix your existing setup.
Note: Make sure to set the Expiration period to Never expire.
Contact support if the delays continue even after setting it up correctly.