Hi,
I recently bought two Roku Express 4k's today as I had one in the living room since I wanted to expand on where I watch stuff. Airplay works with the first (2-year-old) Roku Express 4k but not with these new two (from today). Tested with 5 devices, it prompts a code for airplay, you type it in and say it is incorrect even though it is.
I've tried restarting the router, and the device. I factory reset the devices, tried a custom password (says the same), turned airplay on and off and more but no methods work.