I searched key words for factions, monsters and items and I got nothing from Planescape compendium both in the app and website -- now that I think about, I don't think the content ever showed up for me. Not sure if it's a general issue such as the content is not indexed or if an account issue such as my purchase code was not properly enabled.

Appreciate the help 

I did a test and it shows for me just fine. ¯\_(ツ)_/¯

I search for instance "Dabus", the creature is the sole result of the search. There is no reference to the lore in the compendium.
The same happens if I search "mind's eye" etc. It seems that creatures is the only thing I get from the result (and no, I'm not filtering the results). 
Locations names, regions, lore, nothing appears -- almost as if the book is not indexed.

Quote from LegendmakerGM >>

I search for instance "Dabus", the creature is the sole result of the search. There is no reference to the lore in the compendium.
The same happens if I search "mind's eye" etc. It seems that creatures is the only thing I get from the result (and no, I'm not filtering the results). 
Locations names, regions, lore, nothing appears -- almost as if the book is not indexed.

 
Search Dabus. Click Dabus. See lore.

Here's a video.

Ok, here's a simple way to replicate: try to find the page of Dabus lore you showed me inside the Planescape book as a search result. As your video shows, the only search result for Dabus is the stat block, whereas I should be able to find the actual page inside Planescape compendium as a search result.

The same happens when I search the name of a Sigil faction (e.g. Mind's Eye) in the search: the page from the book containing the lore on the faction does not appear as a result (this lore page should appear as a result to "Mind's Eye" in the search bar --> https://www.dndbeyond.com/sources/paitm/sato/sigil-the-city-of-doors#MindsEye but is not indexed, so it doesn't appear in the search result). 

As a comparison, if I search a faction from Baldur's Gate, like the Flaming Fist, the search result show me the pages with the lore from inside the books (proof: this is the very first link in the search results --> https://www.dndbeyond.com/sources/toa/port-nyanzaru#FlamingFist ).

So, in other words, I'm unable to find content from Planescape using the search bar the same way I find content from other books in DDB. The only way to find these unindexed contents now is to manually scroll through the pages. Get it?

I now realise that this problem is actually MUCH bigger, anything from Planescape and The Book of Many Things that is at the sublevel past the # in the URL doesn't appear as a search result of the type compendium in DDB

I explain the problem here: https://www.dndbeyond.com/forums/d-d-beyond-general/bugs-support/183978-the-book-of-many-things-issues-and-support-thread?page=8#c170

Wow, that's A LOT of pages that users can't find via search bar!!