Stealth mechanic not entirely dependent on Anti-Cloaking Tech/Traits? 5 years ago

As the title suggests, I don't fully understand the stealth mechanics. I've searched around the forums and google, and it seems I am the only one experiencing this. It is possible that mods are to blame, however, I don't believe any of them touch the stealth mechanic.

I have been using the "Ghost" trait for a several custom factions and it doesn't always work. On multiple occassions I have encountered enemy fleets which have no active anti-cloaking tech, hero perks, or system probes, who are still able to de-cloak any level of cloaking tech. I have been able to confirm this, without a doubt, using modding tools and assessing the enemy factions techs, the fleet, and so forth. 

This tends to become less likely in certain portions of the game, perhaps as levels of stealth tech go up, but isn't consistent. The only consistency seems to be that the enemy fleet is larger than mine, parked, guarding the star system, and I have directed my fleet to stop moving in that specific system (as in not passing through to another node). The same has never been true for my fleets, although, the moment I notice there are cloaked enemies I tend to adapt and use anti-cloaking of my own.

My question is this: Is this an intended mechanic? The fact that it always seems to happen in the same scenario has me thinking it is, but I have yet to see any info confirming this. I don't really have anything to add to that. I just want to know I'm not losing my shit. Lol. 

Thanks to anyone willing and able to answer this for me!