Thanks for taking the time to post on the community.
Sorry to read you are having an issue with your printer connecting.
With the Hub 3, it broadcasts both the 2.4 and 5 GHz network as one. To make it easier for your devices to connect to the network, you can separate these with different names and passwords.
To do this type in 192.168.0.1 in the address bar > sign in with the details underneath the router > on the right click into Advanced Settings > Wireless then Security. This will allow you to change the name and passwords of the networks.