Hey @fizzpopmedia
Welcome to the MainWP community!
Since your Dashboard has over 100 Child Sites, we highly recommend enabling Optimize for shared hosting or big networks on the Settings → Advanced Settings page.
In fact, we recommend the use of this feature for all Dashboards with over 30 Child Sites!
It will likely dramatically improve the performance of your Dashboard.
Another tweak that will likely help is to increase the PHP Memory to 1024MB. More info here: Resolving System Requirement Issues - MainWP WordPress Management
And finally, if you don’t see satisfactory improvements after that, please try temporarily disabling 3rd party plugins and see if that helps. Some of them may be using a lot of resources, or there may potentially be a conflict with MainWP Dashboard plugin.