Could you please create XC Api portal with same data from your m3u url and test again? Btw. XC Api portal have more options than m3u playlist.
I did create via portal and all is well so far, but like I said it should work properly with m3u and it should not even be an issue for something that should be so basic. For a box that cost me 200.00 each for 2 of them this should be a non issue.