I purchased Xanthar's so my players could have more stuff available to them. But they can only see 2/3 of the added subclasses. For example, as a ranger they can't see the gloomstalker subclass, but they can see Horizon walker and Monster Slayer. Has anyone experienced this issue and how to fix it?

Tell them to use the 2014 version of the class. (When selecting class the 2024 versions are under 'Core Rules', they need to scroll down to '2014 Core Rules'.)

They are currently using the 2024 version. Some subclasses were remade to the 2024 rules and the 2024 classes can only use the 2024 version of the subclass in those cases, which they don't have so they don't see them.

They should ensure they have enabled the 2014, Legacy and Expanded Rules toggles in the Home page of the builder - they should be enabled by default, but worth double-checking.

Thank you! We figured this out not too long before you posted!