Adding a new mu-plugin does not seem to be working

I am just getting started so hence posted this in the beginners section.

I am trying to install my first mu-plugins and watched the video, did all that was asked of me, however I am not seeing them show up as installed.

The WPMU DEV menu item has no installed items. It should, should it not?

I know the solution is probably simple but I cannot work it out.

Thanks in advance!

Update: Perhaps I jumped the gun or had a caching issue as now they seem to be working. I would delete this post if I could work out how!