Sneak can require cover even when invisible?

Recent DND convert here, DMing my first PF2e adventure (Malevolence).

I am honestly not sure whether this is a design intent or rules lawyering. Sneak action says https://2e.aonprd.com/Actions.aspx?ID=63

At the end of your movement, the GM rolls your Stealth check in secret and compares the result to the Perception DC of each creature you were hidden from or undetected by at the start of your movement. [...] You don’t get to roll against a creature if, at the end of your movement, you neither are concealed from it nor have cover or greater cover against it. You automatically become observed by such a creature.

"Invisible" condition (https://2e.aonprd.com/Conditions.aspx?ID=26) does not count as a cover, neither it is the same as being "concealed" (https://2e.aonprd.com/Conditions.aspx?ID=4). Also,

If you become invisible while someone can already see you, you start out hidden to the observer (instead of undetected) until you successfully Sneak.

So... if a creature becomes invisible while in full view of the party, and then tries to Sneak 10 feet away to a place without cover from the party... does the Sneak fail by RAW?

Full sequence of conditions:

-creature is in view of the party and is observed

-creature becomes invisible, this makes him hidden

-creature tries to Sneak away, but ends its movement without cover and not concealed

-creature can't become observed (as being invisible explicitly prevents it), but it autofails Sneak and fails to become undetected.

Where's the flaw in logic?

Invisible condition, p. 467

You can use the Seek basic action to attempt to figure out an invisible creature’s location, making it instead only hidden from you. This lasts until the invisible creature successfully uses Sneak to become undetected again. If you’re already observing a creature when it becomes invisible, it starts out hidden, since you know where it was when it became invisible, though it can then Sneak to become undetected.

Specific (Invisible) beats General (Sneak)

Invisible condition, p. 467

Quote:

You can use the Seek basic action to attempt to figure out an invisible creature’s location, making it instead only hidden from you. This lasts until the invisible creature successfully uses Sneak to become undetected again. If you’re already observing a creature when it becomes invisible, it starts out hidden, since you know where it was when it became invisible, though it can then Sneak to become undetected.

Specific (Invisible) beats General (Sneak)

I don't think I'm following you. I cited the same paragraph; you become invisible and hidden, you now want to become undetected. Do you require cover to Sneak and do it?

Where's the flaw in logic?

The flaw in the logic is that the clause requiring cover is the general rule, while being invisible provides a specific circumstance in which that general no longer applies.

This is because you don't become observed just arbitrarily because you don't have cover, but because you needed that cover for a reason. And that reason is that it allows you to Hide to become (and stay) Hidden. Because you can't be Undetected if you can't be Hidden. Invisibility takes care of being Hidden, so cover is no longer needed.

The flaw is that the invisible condition explicitly says you can sneak to become undetected.

Also worth noting to a new player - the rule of 'specific overrides general' isn't just a convention that we came up with as players. That is the second of the main General Rules of the game.

Also make note of the last one in that list. It also becomes very important in rule interaction questions like this.

At the end of your movement, the GM rolls your Stealth check in secret and compares the result to the Perception DC of each creature you were hidden from or undetected by at the start of your movement. [...]

Where's the flaw in logic?

You also missed this parts in Sneak:

If you’re undetected by a creature and it’s impossible for that creature to observe you (for a typical creature, this includes when you’re invisible, the observer is blinded, or you’re in darkness and the creature can’t see in darkness), for any critical failure you roll on a check to Sneak, you get a failure instead. You also continue to be undetected if you lose cover or greater cover against or are no longer concealed from such a creature.
Also 'hidden' is stronger than 'concealed' (even if there's no mention of it in the Sneak section) and the requirement is met anyway as I believe.

In hindsight I suppose Invisibility isn't strictly a source of Concealment, tmeven though it is functionally an extra strong Concealed condition (via auto-Hidden instead of merely miss chance)