Wireless thermostats operate at 433MHz or 868MHz - normally. So there should not be an interference issue.
What was the support person taking?
If others are using a channel, you PC and Hub will still see those signals and they will cause you problems and you will cause problems to those networks too. Choosing a channel away from there, as you did, is the right idea. Some suggest 5 channel spacing is best, so 1, 6, 11 but the interference potential when spaced by 4 is quite small. I tend to use 1, 5, 9, 13 (or put my neighbours on 1 and I use the other three).
Channels supporting different numbers of devices ... rubbish!
M H C
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