Page 144 Starfinder core rulebook. Also available at the online SRD: https://aonsrd.com/Skills.aspx?ItemName=Perception
You can use Perception to notice things happening around you. This is the most basic task of the Perception skill. It can be used for a variety of reasons determined by the GM. You might attempt a Perception check to see if you can act in a surprise round, to spot something important out of the corner of your eye, or to realize there are hidden creatures nearby (though you can’t notice a creature that is invisible unless it makes itself known; see page 264).
Page 148 Starfinder core rulebook. Also available at the online SRD: https://aonsrd.com/Skills.aspx?ItemName=Stealth
(Invisible creatures can still be heard, smelled, and felt, and might do something to make themselves known to those who succeed at Perception checks; see Invisible on page 264 in Chapter 8.)
The other person is reading these two texts as meaning: "invisibility is so powerful that you cannot use normal human senses to even notice them unless they are doing one of these things, and if the NPC is not doing any of these things, then you cannot make a Perception check to notice them, and it is DM discretion whether they are doing one of those things", aka it's DM discretion whether I can even roll Perception or not.
With my background knowledge and opinions about how stealth was supposed to work in 3.5 and Pathfinder 1e, I instead interpret these two texts completely differently. I read them as meaning: "Invisible creatures might be invisible, but they're not undetectable by normal human senses. You can totally roll Perception to notice and pinpoint them. What does it mean to notice or pinpoint an invisible creature with normal human senses? If you beat their Stealth check (with the +20 or +40 bonus) to notice or pinpoint them, how did your character do it? Maybe you noticed a cough, or the sound of their breathing, or their smell, or some shapes in the dust on the floor, etc."
I am unable to find any clear text in the core rulebook, online SRD, and online FAQ and errata, that supports my reading.
Perception and stealth have been pet peeves of mine for more than a decade, and I think it's quite clear how it's supposed to work, but I've encountered too many DMs and players that have no idea what's going on.
Thanks for your time and any help you can provide. A quote from a Paizo Starfinder designer would be great. Even an example from an official adventure path would be useful. Equivalently, anyone got a source for using normal human senses to notice or pinpoint the square of an immobile creature in full darkness light level?