I was able to import the M3U into Prismcast, but that's pretty much where the success ended. I put the chrome: etc. command you supplied in 3 Chrome instances: (1) the one that Prismcast opens to do its capture; (2) the "regular" Chrome on my server, and (3) the regular chrome on the most-used client PC (all run Windows 10 or 11). I have the cookie set in the Fast configuration. In Prismcast, I click the button to authenticate the source, and the feed will play, overlaid with a message "click space, or F to play fullscreen; C toggles captions" plus in larger print the name of the channel. At that point I can tell Prismcast that I'm done authenticating. Then go back to the Fast channels list and play it in full screen, and successfully play it there (after clicking a space to clear the overlaid message).
Channels, however, can't play or record this. I can watch what Prismcast is up to while attempting to watch in Channels, and it opens windows titled "about:blank" but they are indeed blank, and nothing plays in channels (running in Chrome for testing this), which displays a message "The media could not be loaded, either because the server or network failed or because the format is not supported."
For anyone who can make any sense of them, here's some log excerpts:
Prismcast logs say:
[2026/06/23 10:58:31.827 PM] [ERROR] [the-carol-burnett-show-jz9ijo] Stream setup failed for http://192.168.2.160:5523/watch/9290: Stream initialization timed out.
[2026/06/23 10:58:31.844 PM] [the-carol-burnett-show-jz9ijo] Stream ended after 10s (setup failed).
[2026/06/23 10:58:31.844 PM] [WARN] Stream setup failed for the-carol-burnett-show: Failed to start stream.
Channels log:
2026/06/23 22:57:56.710592 [TNR] Opened connection to M3U-Prismcast for ch9121 The Carol Burnett Show
2026/06/23 22:57:56.710592 [TNR] Closed connection to M3U-Prismcast for ch9121 The Carol Burnett Show
2026/06/23 22:57:56.728363 [TNR] Opened connection to M3U-Prismcast for ch9121 The Carol Burnett Show
2026/06/23 22:57:56.728938 [HLS] Starting live stream for channel 9121 from 192.168.2.174
2026/06/23 22:57:57.412724 [HLS] Session ch9121-dANY-ip192.168.2.174 started in 683.8024ms
2026/06/23 22:57:58.124515 [HLS] Probed live stream in 1.3943505s: h264 1280x720 progressive 149648bps
2026/06/23 22:58:29.618020 [HLS] Stopping inactive session ch9121-dANY-ip192.168.2.174
2026/06/23 22:58:29.618020 [HLS] Stopping transcoder session ch9121-dANY-ip192.168.2.174 (out=5.322ms finished=false first_seq=1 last_seq=1)
2026/06/23 22:58:29.625135 [TNR] Closed connection to M3U-Prismcast for ch9121 The Carol Burnett Show
2026/06/23 22:58:29.625135 [SNR] Buffer statistics for ch9121 The Carol Burnett Show: buf=0% drop=0%
2026/06/23 22:58:29.625135 [SNR] Streaming statistics for ch9121 The Carol Burnett Show: timeouts=0 segment_timeouts=0 playlist_timeouts=0
