So much for that. It's back to connecting to the router wireless but not the local network.
Try resetting the Roku via Settings>System>Factory reset. WARNING: This will reset all the settings, so only do this if you know all the info/settings saved on the device. This will erase any old settings which may be clogging things up in the Roku.
Also, it seems like the "Roku TV" is the device causing the most problem.
What model is it? My guess is it isn't compatible with fully compatible with AES. When you had the Roku TV connected via WPA, was it set to WPA2
Only?
Just to clarify, the main difference between WPA and WPA2 is WPA2 forces the connection to use AES. WPA can use either TKIP or AES, depending on configuration. WPA/WPA2 or Auto WPA is when the router will first try to connect with AES and fall back to TKIP if it fails. For this reason, I don't understand how WPA2 only can be configured with TKIP. Probably just a UI typo. I mention this because this fall back I think has something to do with the Roku TV connecting, and then disconnecting.