I'm trying to access the aforementioned book, but on both the mobile app and on the desktop browser, it's indicating that I do not have access to it. On the mobile app it clearly says that it's shared with me, but I cannot access it. I am able to access other shared content without issue (at least the few that I've tested at random). 

Is anyone else experiencing this or is it something related to my account specifically.

Thanks!

The DM of the campaign you are in where it is being shared may have disabled sharing for that book. You will need to check with them.

As a DM that also has the Master Tier, I did not realize that you can disable sharing of specific content. I don't even see where that's possible.

Quote from Endersdestiny >>

As a DM that also has the Master Tier, I did not realize that you can disable sharing of specific content. I don't even see where that's possible.

 
A DM of a campaign where Content Sharing has been enabled should have an option for Content Management on the campaign's main page, next to the button used to enable/disable content sharing.

Content Management allows a DM to enable and disable certain books. This only works on "compendium" content - that is reading the digital book source, and has no effect on character sheet options. This is normally used to prevent people reading ahead in adventures that could lead to metagaming as they would be unable to read the book (unless they owned it themselves or had it shared in another campaign where it was enabled).