I recently moved house and bought a Nest Thermostat and I'm having issues operating it remotely from my phone as the app keeps telling me the Thermostat is offline (even though it shows as connected in my Eero app).

After A LOT of trouble shooting, I've narrowed down the issue: the Nest Thermostat requires 2.4ghz whereas the Eero is dual band. I've followed the instructions from Eero to temporarily disable the 5ghz band in order to connect my Thermostat. When I do this, the Nest app on my phone can then control the Thermostat remotely.  The problem is, it won't stay on the 2.4ghz band and switches to 5ghz and I have the same problem all over again.

How can I get the Thermostat to remain connected to 2.4ghz?