For some reason my content sharing doesnt work for some of my players. I have it on, I have everything activated. Example being a player being able to pick some wacky race, but Dark elf of all things doesnt show up for them. It's different for  just about everyone one of my players. 

Turning off content sharing and turning it back on again should refresh the sharing table. Also check your marketplace to make sure your entitlements are in sync.

Edit: Also worth making sure that each character is turning on things such as Eberron / Critical Role / etc. Content on in the sources subsection of the Home section of their character builder if applicable.