Heb 11:1 (1) Now faith is the substance of things hoped for, the evidence of things not seen.
There is an epistemological difference between those things not seen and those things not known.
The writer uses the word hypostasis which literally translates as hypo (sub, below) stasis (stance, foundation, something to stand on), something real. Greek theology however doe snot treat hypostasis as such, but as some sort of substantive reality, as in the "Persons" (Hypostases) of the Holy Trinity.
The way I read Hebrews 11:1 is that "faith is the basis of things hoped for, and a tested proof of things not seen."
No matter how you word it, it doesn't follow, it doesn't make sense. How does he know that this is how it is?
Since you decided to jump into epistemology, just how do you and the author of Hebrews know things not seen (or detected) exist that you may have faith (trust) in them?