So since thelast update my roku wont stay connected 😠 I tried unplugging, system restart, factory reset, modem reset, checking with my provider, cussing, and everything in between. And of course i can not get a human on the phone to help me. I have a roku device since they came out. If this is the kind of customer support they are offering now i will switch to a competitor's device. Absolutely ridiculous!
Furthermore, please be advised that Roku Express is only compatible with wireless b/g/n networks on the 2.4 GHz spectrum. Ensure that your router is broadcasting a 2.4GHz Wi-Fi network for the device to connect to.
Since you are connected to your 2.4 GHz Wi-Fi, try using wireless channels 1, 6, or 11 which are the preferred channels in North America. Each time you change the wireless channel, you will likely need to apply/save changes before you are prompted to restart the router.