timora
I don't see anything to indicate that the b/g/n issue is affecting Viasat but worth looking into. More so, I would make sure to verify that your 2.4ghz band is actually still enabled. Make sure you have two distinct names for the 2.4ghz and 5ghz. Appears that depending on which gateway (router) you have been supplied with, there are different settings that affect which band may be being used.
First thing, look on the bottom of your router for any login/password info on a sticker.
There are different methods of logging into your router and which username/password to use depending on which setting you want to change.
The default methods of logging into this router is to go to a web browser and in the address bar, type in either 192.168.100.1:8080 or 192.168.100.1 This should open your web portal for your router. The username and password are either going to be on that sticker (not the SSID password), or try the default username and password for that router (username=admin, and password=admin)
Then select "Router", and then "Wireless" setup.
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Here are some helpful pages for navigating around the settings of Viasat routers.
https://eguide.field.viasat.com/viasat-wifi-gateway-router-settings-tab/
https://help.viasat.com/s/article/2-4-and-5-GHz-wireless-band
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When you find the 2.4ghz settings, I would try changing the wireless mode to b/g/n and also try changing the wireless channel. (ch. 1, 6, and 11 are preferred). Also, make sure you are using different name for the 2.4ghz band so you are sure you are actually "seeing" the 2.4ghz band as available for connection. Finally, try removing the password for the 2.4ghz password and see if you can connect. If so, then change the password to something simple and see if device again connects.
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Finally, before you start changing the router settings, try to reset the network connection from within the Roku device first and see if this resolves issue. If the following does not work, then look at the router settings. (Make sure to make a note of any previous settings so you can return them to that state if you run into issues or notice any improvement/decline in performance.
1. Restart your router/modem.
2. From the Roku device, go to Settings/System/Advanced System Settings/Network Connection Reset/Reset Connection.
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Feel free to provide further updates.
