Argyle King
Legend
Hide Action: DC 15 stealth check while heavily obscured or behind 3/4 cover, and out of enemy line of sight. On a successful check, you have the invisible condition.
My reading of these rules is that in order to take the Hide Action" a PC must...
1. Be heavily obscured or behind 3/4 cover...
2. Out of enemy line of sight.
3. Make a DC 15 Stealth check
It is taking (and maintaining this action) that bestows the invisibility condition so the moment you are no longer hiding... you also no longer have the invisible condition.
Edit: in other words if you break any of the hide action conditions you are no longer successfuly hidden and thus no longer have the invisibility condition.
I can see (no pun intended) how that ruling would make sense.
However, that is not how the current rules are written. The three conditions you listed are what needs to occur for a PC to gain the Invisible condition.
Once the Invisible condition is gained, the Invisible condition lists the things that cause the condition to be lost.