The first basic troubleshooting is to restart your router and then restart your Premiere. Sometimes, just the restart of both the router and the Roku device will take care of the connection issues.
Premiere will only connect your 2.4gz band of your network wifi. Verify that your 2.4gz band is enabled/broadcast, protocols g/n (mixed) selected, a channel between 1-11 set, not auto or 12,13,14, and your bandwidth is set to 20mhz.
Similar for your hotspot, try setting your hotspot to recognize only 2.4gz, not 5gz, and see if your Premiere now connects.
Basically have to eliminate your network setup as culprit. What happens often is that the Auto settings of a router switches its settings to ones not compatible with Roku, so some manual assignments to the router must be made.
