Iosue
Legend
RAW, a Perception check is a sufficient condition to find a Hiding character. No where is it stated to be a necessary condition.It's literally RAW that it takes a perception check. Unless you take it out of context. The context of "an enemy finds you" is that it is related to "...which is the DC to find you with a Wisdom (perception) check."
I mean this quite clear. It says, “On a successful check, you have the Invisible condition. Make note of the check’s total, which is the DC for a creature to find you with a Wisdom (Perception) check.” This section is not describing the only way you can be found. It’s merely saying the total of your Dexterity (Stealth) check is the DC for a Perception check to do so.
It then goes into how the Invisible condition ends in an entirely new paragraph: "The condition ends on you immediately if any of the following occurs: you make a sound louder than a whisper, an enemy finds you, you make an attack roll, or you cast a spell with a Verbal component."
There is no reason to read "an enemy finds you" as referring exclusively to a Perception check, just because the words "find you" appear in both sentences. "Find you" is not a special term of use that will be in the Rules glossary. There will be many ways for an enemy to find you: Tremorsense, Blindsight, removal of concealment, divination spells and magic items. And popping out in front of them without even bothering to hide anymore.