I have a cleric with a subclass warlock. In my spell list, none of the subclasses expanded spell list, aside from the cantrips, display in my known spells list. How can I fix this? I double checked to make sure we benefit from subclass expanded spell list and found that wizards made sure there were gaps in said lists because of this feature. Equally I couldn't find any settings, on the site, that would allow me to display said subclass expanded spell list in my known spell list. Finally I couldn't find any of the subclasses featured expanded spell list in my known spells list. Any help would be appreciated.

I’m confused:  how can a cleric have a warlock subclass?

Do you mean you have a war domain cleric?

Or do you have a warlock?

Of have you multi classed?

If you character is “just” a warlock, or multi classed as a warlock, and you are talking about the expanded warlock spell list, it works differently than every other spell list.  With warlocks, the expanded spell list means you can choose from among those spells when you are choosing known spells.  Unlike clerics, for example, they are not automatically added to your list of known/always prepared spells. 

For example, if I create a celestial patron warlock, at first level I get to choose two spells I know.  I can choose them all from the “generic” warlock spell list, or I can choose cure wounds and/or guiding bolt, but all total I can only choose two spells.

When you are creating a warlock here on DnDBeyond, you either choose known spells in the character builder, or by clicking on “manage spells” and choosing known spells there.

If you are playing a cleric with the divine domain of "warlock" then that is homebrew and may not have had it's domain spells set up.

If you are playing a cleric/warlock multiclass, the warlock's expanded spell list spells have to be learned as a warlock spell (the same way you would add Hex to the character).

Any specific spells that don't show up may be in a book you don't have access to.