I have content sharing enabled for a campaign, including all source books. However none of my players see anything beyond the base content, even when editing their character from within the campaign

I'll direct you to this thread here, specifically section C. 

The content is available if I look at it, but I can't even get to their character sheet to attempt the inspiration refresh because the character is incomplete in the builder.

Despite being in the campaign to edit, they are unable to see races, or things like Cleric domains (other than Light domain). Both myself and my players have the content entitlements synced (marketplace page shows all is well) 

We've waited 3 days at this point in various attempts to build their characters with no luck or changes to available items. 

What content did your purchase that they are missing? I know you said they only have access to the basic rules, but what specifically did you buy?

I have the entirety of the sourcebooks, and a few minor adventures. The beginning of the issues was after picking up Monsters of the Multiverse, that's when people seemed less able to access things. 

Just in case, try turning Content Sharing off and back on again. That seems to have helped people recently with the same sort of issue.

Gave that a shot, tried turning it off for all campaigns (3 at the moment), and then back on but no luck

Would you be willing, and it's totally okay if not, to make a campaign and post it here to see if we get access to the content? I don't have the MotM book so it would be very clear to me if I had access to the content.

Obviously, if you don't want to do that it's completely fine, and you can always delete it right afterwords. 

Yeah, here's the link *redacted*

I do in fact have access to the content that I don't otherwise have, IE the MotM book. I made a MotM Golbin character just to be sure. Very strange that your players don't have access to it. 

Is it possible that a campaign is bugged? Like it's only the one campaign that I appear to be having issues with

I've never heard of that happening, but it's probably possible. It might be good to see if your players could make a character in a different campaign and get access to your content. If it doesn't work it's probably something on their end and if it does then you can just delete that other campaign that doesn't work for whatever reason.

I added a player to the campaign you were just in and tested, and they do not have access to the content. Attempting to add a screenshot of the limited selection of races. 

*UPDATE* Adding a player to that new campaign caused the "sync your entitlements" button to appear, which resolved the issues

Weird that it didn't trigger with your other campaign but I'm glad you got it figured out!

Also probably worth taking down that link now so you don't get randos popping into your campaign. 

Good call, and all set! Thanks for your help 

Of course! Happy to help!