I figured out a fix, but I still do not know why they were not working originally
The fix was to copy the html code from the text editor part of WordPress from one of the tracks that WAS creating the embedded player correctly - from a link that was working - and then paste that code into the text editor part of the page, where the payer was not working, and replace the link with the one that hadn't been working before, and, boom it worked. Then I switched the page back to Visual (from text view) and updated the page and it worked fine.
I tried copying the code here, but it just turned it into a link. - of course it won't show here
I went into one of the ones that IS working correctly and copied the code around the link, the container etc and pasted it into the text editor of my theme, then placed the embed link, and it worked perfectly. I did that with the three links that were not behaving correctly. and when I did that and added the correct links - they worked.
But I still don't know why the last few links I tried to add, will not automatically re-create the player in my theme. With all the links, I selected share on the appropriate track, copied the link and pasted it into my WordPress site, but with 3 links, it did not create the player, the others worked - until I used the work-around as stated up top.
I am using Elegant Theme's Divi theme, and this morning, I updated to the latest version of WordPress 5.1, although it was also doing the same thing Friday, when I was at 5.0.3? or whatever was right before 5.1.
The only other factor I can say is that the interviews are private on Sound Cloud - we are not interested in having them posted to itunes and all those other places, just on our site.
Original post: I was uploading a series of private interviews to a WordPress site and for some reason - two of them won't create the player - all the rest on the page do, except two of them? any idea why? I tried creating a new link, but the same thing happened. - I have left them as links to the sound cloud, and they play fine, but they don't create a player on the website - like all the other links do.