I bought a new TP-Link AX1800 Router to replace my old AC3150 router. I set the same SSIDs for the 2.4 and 5gHz networks, and set the same passwords and security settings.
All my 5gHz devices connected to the new router no problem. And some 2.4gHz devices connected to the new router.
But some 2.4 gHz devices would not connect. They see the new network as being a different network when I plug in the old router. For example on my laptop there are two 2.4gHz networks with the same SSID, but they are listed separately. The 5gHz networks are recognized as being the same, so only one 5G network is listed.
Any thoughts on what is causing some devices (Google Nest Hub, Rachio smart sprinkler, Kasa wifi light switch) to not recognize the new network as the same as the old one? If it matters the SSID has capitol letters and a space in it.