I am suprised this isn't a feature already, but there should be an ajax notification for new inbox messages.

So I will be notified that there is a new inbox message without having to reload the entire site.

This is an ajax notification about a new private message:

On 2/27/2022 at 12:35 PM, Adriano Faria said:

This is an ajax notification about a new private message:

 

But from my experience it requires a page reload, it does not check the inbox every 2-3 second?

Nope. It happens without a page reload. It can happen midway through typing a reply to a post. 

10 hours ago, OctoDev said:

 

But from my experience it requires a page reload, it does not check the inbox every 2-3 second?

As Randy said, no page reload is required. I’m not sure how many minutes or seconds it takes to check but definitely no reliad is required. You probably have a JS issue in your board.

Or possibly Ajax disabled in theme settings