@xmacj Perhaps the remote side didn't like something about your original ip address.
I have an ecobee premium (upgraded by ecobee due to wifi issues on a ecobee 3 lite - data drop outs, morse code).
No wifi issues (it's bound to 2.4ghz band). But it does like to phone home to amazon every 50s. None of the amazon features are enabled, but it still insists.
To mitigate this, 2 different measures are in place. On the dns side, only requests to *.ecobee.com are resolved (adguard home). All others return 0.0.0.0 .
On the pfsense side, amazon asn is blocked for this device just in case the dns filters are off (sometimes happens during testing).