<snip> I've got a Hub 3 that's in modem mode, using an additional router. Have tried resetting both the hub and router to no avail.
VM will ask you to put your Hub 3 back in Router mode for diagnostics.
When done, can you post your power levels and network logs. Also setup a BQM here to monitor your circuit. www.thinkbroadband.com/ping
Once done we can comment.
You could also try a 60 second factory pinhole reset as below;
Remove any ethernet cables from the Hub and hold the pinhole reset switch for 60 seconds. Do NOT reboot the Hub, just let it do it's thing. Note you will need the passwords from the bottom of the Hub afterwards, so make sure they are legible.
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