Ability to diagnose Node issue

I have 3 eero Pro's, all model B010011 and running v6.11.1-46.

The TLDR:

For 10 days I had my phone and streaming devices buffering, overall crappy internet.  I went back and forth with XFinity....bought a new modem.....more back and forth with XFinity, finally had a tech scheduled to come this AM.  Last night, I thought, let me try one last thing.  I connected a spare router I had, disconnected eeros and all issues went away.  Plugged eero back in, ran a speed test near a node downstairs, 300+ on wifi...went to 2nd floor, 3mb....tried 3rd floor 300+.

My suggestion is, a diag tool that can be run by the user or is run automatically that would test the integrity of the node.  I could have solved this 10 days ago if I knew it was the node.  Once I took the 2nd floor node out, everything is back to normal.