The Google Drive app does not work with any proxies that perform SSL decryption as a security measure against interception. If you've enabled HTTPS Inspection in your Web Policy and deployed the Umbrella Root Certificate to all machines, you will need to perform some extra steps to get the Google Drive app working. Also note, if you login to the Google Drive website, uploads will likely work fine so this is only related to the app itself. If you disable HTTPS inspection the app will work, but will lower your Umbrella-related security posture which is not recommended.
In order to use the Google Drive app with SWG while SSL Decryption is enabled, the following steps must be performed.
Umbrella Configuration Changes
1. Log into your Umbrella Dashboard as a Full Admin user
2. Navigate to Policies --> Management --> Web Policy
3. You should see HTTPS Inspection Enabled
4. Navigate to Policies --> Policy Components --> Selective Decryption Lists
5. Create a new list or edit an existing list
6. Click "add" next to Applications Selected, select Google Drive from the list and click close
7. Click "add" next to Domains, add the following two domains then click close and save
8. Navigate back to Policies --> Management --> Web Policy and edit your Web Policy
9. Locate HTTPS Inspection and click "Edit"
10. Select the Selective Decryption list you just made the changes to then save your changes
Wait a few minutes for the changes to sync over, then Google Drive should work normally.
Note: Google domains are subject to change at anytime. Please refer to this article for any updates.