I added a single sorcerer class to my paladin and instead of adding two first level slots, it added a single second level slot.

To test it, I added three more levels of sorcerer and it added two third level slots and a fourth level slot.

Something is broken in the database.

Link to character here.

https://www.dndbeyond.com/characters/66757565

It’s working correctly. That’s how it’s sposta work. You should reread the rules for multiclassing.

Um.  I am pretty sure a 4th level Sorcerer doesn't get 4th level spell slots.

You are correct, a 4th level Sorcerer doesn’t get access to 4th-level spell slots. However, when multiclassed with another Spellcasting class, such as Paladin, counts as a higher level Spellcaster when determining spell slot progression. As I stated previously, read the Multiclassing rules:

Spellcasting

Your capacity for spellcasting depends partly on your combined levels in all your spellcasting classes and partly on your individual levels in those classes. Once you have the Spellcasting feature from more than one class, use the rules below. If you multiclass but have the Spellcasting feature from only one class, you follow the rules as described in that class.

Spells Known and Prepared. You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class. If you are a ranger 4/wizard 3, for example, you know three 1st-level ranger spells based on your levels in the ranger class. As 3rd-level wizard, you know three wizard cantrips, and your spellbook contains ten wizard spells, two of which (the two you gained when you reached 3rd level as a wizard) can be 2nd-level spells. If your Intelligence is 16, you can prepare six wizard spells from your spellbook.

Each spell you know and prepare is associated with one of your classes, and you use the spellcasting ability of that class when you cast the spell. Similarly, a spellcasting focus, such as a holy symbol, can be used only for the spells from the class associated with that focus.

Spell Slots. You determine your available spell slots by adding together all your levels in the bard, cleric, druid, sorcerer, and wizard classes, and half your levels (rounded down) in the paladin and ranger classes. Use this total to determine your spell slots by consulting the Multiclass Spellcaster table.

If you have more than one spellcasting class, this table might give you spell slots of a level that is higher than the spells you know or can prepare. You can use those slots, but only to cast your lower-level spells. If a lower-level spell that you cast, like burning hands, has an enhanced effect when cast using a higher-level slot, you can use the enhanced effect, even though you don't have any spells of that higher level.

For example, if you are the aforementioned ranger 4/wizard 3, you count as a 5th-level character when determining your spell slots: you have four 1st-level slots, three 2nd-level slots, and two 3rd-level slots. However, you don't know any 3rd-level spells, nor do you know any 2nd-level ranger spells. You can use the spell slots of those levels to cast the spells you do know — and potentially enhance their effects.

A 4th level Sorcerer doesn't have 4th level spells, but a 7th level multiclassed spellcaster does. Per the Multiclassing section of the Basic Rules (which I agree with Sposta, you should reread. It took me 5+ times to figure it all out), "You determine your available spell slots by adding together all your levels in the bard, cleric, druid, sorcerer, and wizard classes, and half your levels (rounded down) in the paladin and ranger classes. Use this total to determine your spell slots by consulting the Multiclass Spellcaster table." (6/2) + 4 = 7, and a 7th level multiclassed spellcaster gets 4 3 3 1 slots (in order from 1-4).

Note that you can't actually learn 4th level spells, however. You can only upcast lower level spells, because neither a 6th level Pally or 4th level Sorcorororor know 4th level spells. The pertinent rule text for that is in the same above link.

ah.  cool.

As I said earlier:

Quote from IamSposta >>

It’s working correctly. That’s how it’s sposta work. You should reread the rules for multiclassing.

I wouldn’t lie to you.