I've downloaded the Player's Handbook (2024) in the mobile app (on Android if that makes any difference). I used the Table of Contents (button in the top right corner) to access the Spell Descriptions. Multiple spells that are listed in the web version (https://www.dndbeyond.com/sources/dnd/phb-2024/spell-descriptions) are not listed in the PHB 2024 in the app.

I first noticed Melf’s Acid Arrow was missing.

https://www.dndbeyond.com/sources/dnd/phb-2024/spell-descriptions#MelfsAcidArrow

I then went through the A section and all the following are missing.

https://www.dndbeyond.com/sources/dnd/phb-2024/spell-descriptions#ArcaneGate
https://www.dndbeyond.com/sources/dnd/phb-2024/spell-descriptions#ArcaneVigor
https://www.dndbeyond.com/sources/dnd/phb-2024/spell-descriptions#ArmorofAgathys
https://www.dndbeyond.com/sources/dnd/phb-2024/spell-descriptions#ArmsofHadar
https://www.dndbeyond.com/sources/dnd/phb-2024/spell-descriptions#AuraofPurity
https://www.dndbeyond.com/sources/dnd/phb-2024/spell-descriptions#AuraofVitality

I have not gone through the other letters of the alphabet, but I expect there are more missing in B to Z.

Same here, the spells i got on my mobile app (ios) 2024 PHB are the ones that are in the 2024 free rules… works fine on browsers, in app characters or in app listings though 🤷‍♂️

I’ve also encountered this problem. Does anyone anticipate a fix soon?

Same issue here.

Seems like they fixed it with the latest update. 

Yep, after downloading the update I can now see Melf's Acid Arrow and all the A spells I listed in the first post above.

@D&D Beyond staff, thanks for fixing this.