@The_Zealot Ensure both phone and Tv are on latest software, restart both Devices. Other connection methods detailed in this article,Panasonic may not be compatible with Smart Things though. https://www.samsung.com/uk/support/tv-audio-video/what-is-screen-mirroring-and-how-do-i-use-it-with-...
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 5.0,Android 13 .