I have just bought a new printer which only works with 2.4 GHz connections.
This printer will not connect.
On investigation I find that everything else that connects to the hub - PC, smartphone, etc. - have all connected at 5 GHz, notwithstanding that the hub is set to handle both 2.4 GHz and 5 GHz.
Do I need a new hub or is there a magic setting that I'm missing?
Try temporarily turning off the 5 GHz wifi connection on your VM hub (be aware though that when you do, all your 5 GHz devices will be temporarily disconnected while it is off).
While the hub is broadcasting on just 2.4 GHz, try connecting the printer. If it connects, turn the 5 GHz back on again and see if the printer connection holds up.
Devices with basic wifi, such as printers, may not like the combined SSID wireless name from the VM hub. Temporarily turning off the 5GHz may allow the printer to connect to the 2.4GHz signal)