[Milhouse]

With LE8 and Kodi 17 were no problems with mmal player.

That suggests that mmal will work as desired with one on the older builds from here (perhaps a couple of months back).
Narrowing down the first build with the problem would be useful to identifying the commit that caused the issue and hence finding a fix for it.

When I go back to LE8, does Amazon work then or not?

Greetings Cosmicbase

No, there is no Amazon support in LE8 - it's currently only in these test builds.

However what popcornmix is asking is for you to go back methodically through the LE9 test builds in this thread until you identify when the playlist problem started - I normally start with a build from 6 months ago (eg #0101) and if that works, try #0201, if that works try #0301, if that is broken you know the problem is between #0201 and #0301 so now try #0215 and repeat the process until you identify the single build where the problem starts. It's possible the problem may have been introduced more than 6 months ago in which case go back further until you find a working build then work your way forwards. It's tedious, but usually very effective...

Once you've done that you can return to using the latest test build (with Amazon etc., but broken Youtube playlist). Popcornmix stands a much better chance of fixing the Youtube issue once he knows when it stopped working, then you can have both Amazon and Youtube playlists.