Try thinking of it as the SH2 router has two ‘paths’ to the ‘internet’ , the usual path is via the ‘landline’ broadband and a reserve back up path is via mobile 4g , should the landline service fail , the router switches over to using the 4g service , you (or more accurately your devices) still connect to the router in the same way they always do, they don’t care if the router is using the primary ‘path’ or the back up ‘path’ , from your device point of view , the path the router is using to the ‘internet’ doesn’t matter , they have a path …..it just may not be as fast etc as the primary path ,
