I am experiencing an issue on both iPad and iPhone app where compendium content is not displaying properly.

Regardless of display setting it seems all books display as plain text, which makes the overall experience much less appealing.  It also makes tables basically unreadable, 

I have uninstalled and redownloaded the books, updated the app, all with no effect,. Any assistance would be appreciated.

I'm having the same problem. Did you figure out or get a solution?

not really.  i removed all the content, updated the app and redownloaded seemed to fix it.

Years later and this is still an issue. Books look great on iOS (phone) but awful on iPadOS (tablet).