Hello, I am having problems playing most UHD BDs. I leave an example for you to see. My configuration is 4k@24 fps and I have the latest firmware 2.388 installed
No, not seen a problem like that. You say your configuration is 4K24 - I assume that's just the GUI and you have auto framerate turned on since that movie (like most) is 23.976 not 24fps. I always set the GUI to 4K23. Also, try ripping to MKV - much more reliable.
Exactly, I have auto framerate turn on and in this case i didn't see changes between 23 o 24 fps. Yes I Ripped the iso to MKV and it worked perfectly.
I'm afraid BD Menu support is, shall we say, problematic. Mostly it works, sometimes it doesn't - this may be a symptom of that. The Z9S is quite an old box now and I've no idea where it got to with BD Menu support before support stopped, but it was a few years ago now. I always use MKV - IMHO BD Menus are pointless time vampires at the best of times - MKV support is pretty much bomb proof.