When should we contact the editor to follow up on our submitted manuscript?
No, it's way too early for that. Calm down and be patient.
The quoted averages are just that, averages. There are necessarily some pretty wide distributions around them, given that it may take the editor a while to find suitable reviewers, and then the reviewers have a couple of weeks to do their job (and many of them are routinely late). I would give it at least a month more before reaching out to the editor.
Additionally, there is a couple of points to consider:

It's summer in most of the world, so everyone is on vacation (or &quot;staycation&quot;) these days. That makes everything take a little longer than average.
Everyone around the world is still a little distracted by the pandemic and the related work disruption, so long-term averages no longer match the current situation.