NETGEAR WAX214
Warning
Work in progress. Documenting current sporadic issues.
Access point. Seems to have some sort of issue with the 2.4GHz radio as it can't select a channel nor broadcast the IoT SSID. This is only when the first network in the list doesn't have the 2.4G radio turned on, otherwise it seems to work properly.
As part of diagnosing the issue, disable all wireless networks apart from the IoT SSID and enable that only on one band at a time. In my instance, I found that the IoT SSID wasn't broadcasting on the 2.4G band, only the 5.8G band, which meant that all looked okay on my phone, but the cheap radios in each plug are not enabled in the 5.8G band, so we use the 2.4G band for them.
When the radio is not working correctly, this means that the devices cannot connect. To fix this issue, the #1 SSID in the list needs to be enabled seemingly on only the 2.4G band along with the IoT SSID (#3 in my case)