I have a Samsung 24 Ultra phone and a Roku Streaming Stick 4k. Both have the latest updates as of 29 August. I use this device for when I am traveling and staying in a hotel. I have the device setup and it works perfectly on the hotel's Wi-Fi network and the Roku remote, but while the device is listed as being in my account, the Roku app will not connect to or detect the Streaming Stick 4k, even when manually entering its IP address.
My phone and the Streaming Stick 4k are both on the same Wi-Fi network (10.11.xxx.xxx).
For the record, I have 4 Roku Ultra's on my previous home network and all worked fine with the app.
I have reset the network connection on the device, but it doesn't give me a "clean" connection, in that it doesn't ask me to enter passwords or verify other info as it did the very first time I set it up.