I have one specific character for whom level 4 spells do not appear on the character sheet. Everything else works fine, and no other character has ever had this issue.

Link to the character?

Do you mean level 4 spells are not available to learn or learned level 4 spells are not shown?

Is it a level 7 full caster (or level 13 half caster)? Did you multiclass?

There is a minimum amount of information needed to help.

Not shown. They can be learned fine.

Half caster; cleric and warlock. Also, there seems to be a new problem in that sheets aren't loading, but that's happened before.

I'm having issues with my character sheets too. Likely a separate site wide issue.

You can still post a link to the character to be viewed when available. What is the class level split?

Cleric 6, warlock 14.

https://www.dndbeyond.com/profile/BillPoole/characters/5711696

 Oh. Well that is just because you don't have any level 4 spell slots, so they are all upped to level 5. Warlocks.

Quote from DxJxC >>

 Oh. Well that is just because you don't have any level 4 spell slots, so they are all upped to level 5. Warlocks.

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Thank you.

*bangs head repeatedly against a hard object*