I tried dropping the .m3u from the link in TV streams and it still says failed to stream. However, when I do the same thing in chrome it shows a long text only page with technical info for each channel.
The text only link is the one to use for adding a “Playlist”, I think.
The .m3u links to specific channels is what to use if you just want to add individual channels.
All of my specific live channels are .m3u8 links.
Also I never even bothered generating the list of channels in .m3u form. I just manually the channel number (of the live TV I would want) into the URL syntax mentioned in the first post.