Last few years Honeywell has been horrendous in terms of stability of their cloud infra - it would go down morning EU time, then again morning USA time, if it is/was even remotely cold. I’m using an Evohome system, but it seems to be the same infrastructure for most (all?) of their connected products.
I got to the point of about 20 outages in less than a month, when I gave up counting. Their support basically apologises, then ignores you…that’s if they acknowledge the outages at all. Their stance seems to be to ignore it, wait until it gets warmer, then their infra can cope.
I’ve recently started playing with the below, with nanoCUL, so that it can be controlled directly without Honeywell cloud. It’s getting pretty good, almost at the point where I can ditch the internet gateway/connectivity completely.