@Shvance
Roku devices do not currently support the 6ghz band.(wifi6e)
Roku-branded Pro/Plus RokuTVs and the newest Roku Ultra 4850 do support WPA3 and wifi6(ax) but still only on the 5ghz band.
All other Roku devices that have dual-band support and do not support wifi6(ax) will need to use WPA2 protocol on the 2.4 and 5ghz bands.
There is an additional subset of these dual-band Roku devices that do not support DFS channels (52-140) on the 5ghz band, so may need to disable that as well on the router. The current lineup of Roku devices generally support DFS. (some Streambar model exceptions).
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
Insignia RokuTV, Ultra 4660, 4802, 4850, Premiere+ 3921, Express 4k+ 3941, Streambar 9102