Unable to view partnered content on my account, but others can in same campaign

I have a character in a campaign with content sharing enabled. It's only.partially working. 

The character is using the Monster Hunter class from grim hollow. I want to give them the feat "Thrown Weapon Master" from grim hollow as well. However, when I use the level 8 ASI, grim hollow feats don't show up. They also don't show when using manage feats in the full sheet.

I have confirmed that grim hollow is enabled, and content sharing is turned on. The character still has the class from grim hollow, I just can't add and other items from that book to those characters. 

It gets weirder. If I unassigned the character, and have the person sharing content claim them, they CAN see and use the content. No other settings, stats, or selections change. 

I was able to pick the class. Even the weird grim hollow weapon masteries. Why is this happening???

Are your entitlements synced?

That fixed it! I didn't even know this was a thing to check. You would think it would have some kind of auto sync

Regardless, thank you!

It does auto sync, but it's buggy/flaky/cursed, so sometimes it doesn't, or gets out of whack, so there's the button.

I wish there was a better option than DND Beyond. It's just so garbage, entirely by design and intentionally. 

I miss HeroLab, or MPMB's scripted character sheet PDF. They were all so much better, actually had support, and were designed from the getgo to work more often.