Richard wants to connect his smart plugs to his Google Nest mesh router. But they aren't connecting. Leo says that Google Nest Mesh is a dual-band / tri-band and the smart plugs are looking for just 2.4 GHz. It's possible that they have mistakenly attached to the 5 GHz band because its signal may be stronger. Some routers allow you to turn that radio off and the plugs should connect. Once it's paired, you can then turn the 5 GHz band back on. But according to Google support, that doesn't work on the Google Nest because you can't turn it off. Here's an article for more information. Here's a workaround. The Guest Network on the Google Nest WiFi may only be 2.4ghz only. So try setting up your guest network just for IoT devices. That's the way to go.
Brian says you can create a separate wifi hotspot on 2.4ghz and it fixes the problem.