@akwyant-
Check your router configuration. I'd expect most any 5 Ghz router to also support the 2.4 GHz band. If so, it may just have the 2.4 Ghz band not enabled. If possible, I'd suggest giving the 2.4 GHz band a different network name (SSID) to make it easier to keep track of when connecting devices.
Roku Community Streaming Expert
I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well.
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Ultra 4800 | Streaming Stick 4K+ 3821 | TCL Roku TV 43S245/C107X