@dgerety,

I believe this is the bandwidth currently passing through the network, as similar screens can be seen for each node. The overall speed test feature was removed from the app due to inconsistencies and misunderstanding of what the results meant.

Here are a few things for you to try:

Change your network's DNS server to a common service such as Google's or Cloudflares servers. Depending on your location you may have a much speedier experience with these servers.

Make sure that you have disabled private addressing for your home network. This is in your phone settings and will prevent your decos from identifying your phone between disconnects.

You may try looking in the Deco app to make sure, in the times where you see the slowdown, that the MacBook is connecting to the node you think that it is. I would also recommend trying to space your nodes out a bit more than it sounds like they currently are - if they are too close, your device's connection may bounce around between nodes or it may simply serve as a source of interference for existing connections.