That software works with something else does not prove or disprove anything. That's how bugs are. They can be triggered by a certain set of circumstances.
So be patient and don't jump to conclusions.
I'm not jumping to conclusions, I'm only reporting that the same 1:1 BD folders rips plays fine with two different hardware players, but don't play with JRiver MC.
I'll let Hendrik conclude if something could/should be done so that JRiver MC supports these titles too, or not.
I've offered to provide the disk structure of one of these titles in order to help reproduce the issue, if Hendrik doesn't have access to any of the recent Paramount 4K UHD titles I've listed.
Anyone with the titles listed above or any recent paramount 4K UHD bluray title can also try to reproduce the issue (play them with JRiver and bluray menus enabled) and report their results, as well as the tool used to rip their title if it's not AnyDVD. That way you might get more data points if needed.
To clarify, I'm not asking for any help or any immediate resolution. I've reported an issue and am happy to help if needed, when/if the developer decides to look into this. That's all.
For now, I'm perfectly happy with Hendrik's reply.