This is more of a Ne-aux take on it, but perhaps helpful still...
I sometimes have the problem of "just knowing" a current, but "hidden" reality & being unable to support it with anything concrete. Because I see something happening that's not obvious to others, I can guess the next step in the pattern.
I think it's a bunch of semi-unconsciously perceived stuff being fit together in the background of my head until at once I get a whole realization. This happens for me concerning people's motives a lot. I don't consciously note body language or analyze a comment they make, etc. But one day, one small thing can trigger all this seemingly unrelated stuff to come together & give me an overview of "what's really going on".
I've gotten better at straining my brain to recall details to support my conclusion. I'll chalk this up to better Si with age. But once I do that, the details can fade out again. You know that movie Eternal Sunshine? I think Jim Carry's character is Si-dom. My mind is kind of like his as the memories are being erased, and then he's just left with this hunch that something is/was/could be. It's more like I have the hunch, then as I try to bring back the details, they sort of erase out after confirming my hunch. I'll sometimes be left with a few of the strongest details which support my hunch, which I then probably remember in an exaggerated manner. Again, I think this is an inferior use of Si.
Sometimes, I try and write stuff down as I recall it. This sounds like paranoia, now, as I type it... Let me assure you I don't record daily details in case I need to prove something later. I mean, in retrospect, I may journal some thoughts on why I feel a certain way, and whatever details I manage to pull up from memory or some other source will be listed & sorted there. On some occasions, this has actually tempered my view as once "facts" are listed & sorted, my hunches & feelings may seem less valid. I sometimes can't see the trees for the forest, then, and this can ground me so I'm better able to realize the trees are bushes & it's not a forest after all, but a thicket.
Because I am able to recall details, even if with difficulty, I've realized stuff DOES strike me in the moment, but unlike a Si type, I often don't seek to immediately connect details to anything & slowly build impressions. Instead it just kind of gets tossed into a murky pot where hunches brew, and later on, you don't know exactly went into the sauce. Dissecting it is like guessing the ingredients by final product when you have no recipe.
Sometimes I talk to another person, which in the case of Ne, helps me plot my own jumping between all those contexts so I can see how I connected the details, but consciously this time. I kind of relive my original realization in bringing the other person to the same one. It helps if they've experienced many of the concrete details I did, because then they support my foggy memory & I know I'm not paranoid.
I've had a lot of useful conversations with my ISFJ mom about stuff like this. Sometimes I get told I'm paranoid, sometimes I'm vindicated later as supporting details or even my full conclusion finally emerge as visible to others, and other times I successfully get people connect it all as I do and become aware of a reality I see.
It's also not unusual for someone else's observation to provide the "trigger" that causes me to finally realize a big picture. I think this is because their perception of something concrete is a needed support to the hunch that's been shaping up somewhere in my head, because I can push hunches down/dismiss them since I struggle to support them factually.
So carrying around a Sensor buddy in your pocket might help. Give them a notepad, and take some mental pictures yourself.