I have quite the mystery that's just come up and would LOVE to figure out the fix. Both myself and my roommate have smartphones from Sprint, Note 6 and Note 9. We have three smart(enough) tv's with three different roku boxes (all Premiere+) and we have been able to cast to all of them via our phones for the last couple of years just fine. NOW, as of yesterday neither of us can cast to any of the boxes. However my laptop will find the Rokus and can cast just fine. I tried using three different casting programs and none of them even see the Roku's. The casting icon has disappeared from my Youtube app altogether! ALL products are up to date. I have reset the mode, router, roku's and phones. All devices are on the same (the one and only) wifi network. All Roku's work fine as you can watch Netflix, Hulu, etc on them just fine.
ANY HELP is greatly appreciated. Thank you very much!!!