I have an old Ooma Hub (have a Telo too but it is still in the box) that has been acting up lately. Today it just wouldn't work (couldn't properly connect to the network). I tried moving the Hub closer to my cable modem (I have a cable modem-->Firewall/Router-->switch 1 -->switch 2 --> Ooma Hub). It worked when I connected it to switch 1. I ended up power cycling switch 2 (8 port unmanaged switch) and the Ooma was able to connect as usual and is working again.
Strange fix, but thought I'd throw it out there in case others are having a similar issue.