Some time ago I noticed that Flock of Familiars isn't appearing anymore on my Warlock spell list. I'm just looking for insight as to why this is? Is it due to some fault of my own? A bug of the site? Clarity would be appreciated greatly! Cheers!

Flock of Familiars is only available from the Lost Laboratory of Qualish adventure. We’re you previously in a campaign where that content was being shared?

That's the thing, I have the book purchased and available to me, but the spell isn't appearing for me.

Edit: Checking back, I don't have access to Galdur's Speedy Courier or Galdur's Tower either. Wizard is missing out too. 

Go here and make sure that your entitlements entitlements are synced:

https://www.dndbeyond.com/account/marketplace

Everything looks okay, (un)fortunately. I just put in a help ticket as well to see if that would help at all. 

Is that adventure “non-core content” by chance? If it is, then on the “home” tab of the character builder the toggle needs to be on (red, to the right).