I have an iPhone 13 on iOS 17.7 and a Roku Express 4K+ connected to my Samsung TV. My Roku app somehow disconnected from the device and simply refuses to reconnect over WiFi or via IP address. It tells me when I try that method that “A Roku device was not found at this IP address.”
This issue happened suddenly for me a few months ago, for the first time in over 2 years of owning the Roku device, but I since lost the solution I had found for it at the time (I recall it being in my phone settings, where I turned a setting I had never heard of off and on again). Nothing regarding my internet service has changed since then.
I can confirm that the Roku device and my iPhone are on the same network; I have the Local Network setting enabled in my iPhone settings and the Control by mobile apps setting in the Roku set to Default; I have restarted both the Roku device (also unplugged it and plugged back in) and my phone; I have reinstalled the app on my phone; and all my software is up to date. NOTHING is working to fix this. It is most certainly not an issue with my router. I am at a loss for why this is happening and need creative solutions, as none of the responses to similar posts in this forum have been helpful. I can provide serial numbers etc. if necessary.
It is upsetting how common a problem this seems to be for Roku users, and I hope it gets resolved if its cause is internal.