I return to this topic,
because in addition to the convenient use of the "jacadcaps" converter
https://tunkki.dk/~jaca/player.html

I tried using "AmiTube" to watch videos on "TwitchTV"
and it works very well.

probably it is a problem of "ffplay" (version.4.4 Morphos)

while with 4.1FE ("ffplay" and also with "MickjT-MPlayer")
AmiTube to watch TwitchTV works perfectly
here the examples:

MickjT-MPlayer (720p)
https://we.tl/t-mVmvpFp6XH
FFPlay (360p)
https://we.tl/t-qCSk3EFhim

instead with FFPlay for Morphos sometimes it works and sometimes it doesn't.
here the example:
https://we.tl/t-nJ56DOgYsI

a new version of "FFPlay" (Morphos) would be needed
or I can add parameters in the command line such as:
or something similar to solve the problem?
"-loglevel quiet -infbuf -skip_loop_filter all -skip_frame noref"
to prevent streaming from crashing?

Thanks for any suggestions.