Extension Updates
Extensions automatically update to the latest version, except for partial rollouts which are meant to test changes to a small % of users before I push it to everyone. This prevents most people from seeing any issues at all. Those changes may take 1-2 weeks for everyone to get the update or you can force updates (see below). Visit the Changelog for all the details on the updates.
If you see a bug you were probably in that small % test group so please report the bug.
Force updates
Click
Firefox: Go to about:addons > Extensions > Settings button > Check for updates
Different versions and stores
The Chrome, Edge and Firefox stores have varying review process delays which can lead to different versions. The solution is simply to be patient.
Update notifications
You can select the type of notification updates you want to receive in the extension options for the Gmail extension. From none, new features or all updates.