@B3NNYB0Y - yes, I've seen similar behaviour with all my Google kit.. the BT SH 2 confuses the hell of them and don't get me started on the Whole Home WiFi.. I couldn't even see half the devices when they were on the same SSID / frequency.
Ok.... Results so far are working. The SH2 is supplying 2.4GHz band and the Devolo 1200+ is supplying 5GHz band, (network name example 2.4 = MYWIFI, 5.0 =MYWIFI-5GHZ) so the SSIDs are different.
I've connected my smartphone to the 5GHz WiFi supplied by the 1200+ home plug and I can communicate with items on the 2.4GHz band. No issues so far, like how I saw when 5GHz was enabled on the SH2.
It's early days as I will need to try plugging the 1200+ nearer to the network source plug, as the download speeds are not as fast as I expected (compared to that of the SH2 when the 5GHz band was enabled).
One small oversight in my so called cunning plan..... I thought that I could possibly run a network cable direct from the SH2 direct to the 1200+ WiFi plug, BUT it seems the configuration is to have a non-WiFi Devolo plug with network cable to the router as providing the source network traffic, which is what I currently have, and then plugging in the 1200+ elsewhere. It seems the wiring in the walls are limiting the network speed.
I'll try another thing, by flipping things around.... (don't know why I didn't think of this earlier!)
I am going to try enabling only the 5GHz band on the SH2, and having only the 2.4GHz band via the "1200+" home network plug. Again rather cumbersome, but that way I should be able to get faster download for sure like before for the newer devices with the 5GHz band directly coming from SH2 delivering the fast broadband.
The 2.4GHz devices should be fine working at the lower speeds.
The caveat.... How I choose the WiFi names may save me a bit of work and avoid having to re-introduce all the 2.4GHz devices on the WiFi LAN.
Useless piece of junk does not support different sidd for 5G makes older devices useless unless you are prepared to run everything on 2.4
Devolo Support confirmed that you can connect the Devolo WiFi 1200+ directly to the SH2 and the download speed over the WiFi 5GHz (from the Devolo) band is much faster. But the 5GHz signal does travel as far as the 2.4GHz band so there is a caveat.
Above all though, it is very very short sighted of BT to stop the SH2 from supporting separate bands with different names. Can they (or anyone) please explain the technical problems that would happen if they amended the firmware to do this. To me it makes no logical sense at all removing the feature.