Source?

This is all I could find on the subject:

nonceliac gluten sensitivity (NCGS), has resurfaced in the literature, fueling a debate on the appropriateness of the GFD for people without celiac disease. Although there is clearly a fad component to the popularity of the GFD, there is also undisputable and increasing evidence for NCGS.

https://pubmed.ncbi.nlm.nih.gov/25583468/

And:

NCGS is included in the spectrum of gluten-related disorders.[3][4] The definition and diagnostic criteria of non-celiac gluten sensitivity were debated and established by three consensus conferences.[4][14][15][16][17] However, as of 2019, there remained much debate in the scientific community as to whether NCGS was a distinct clinical disorder.[18]

So there’s definitely debate in the community about it, I would love to see some of these many tests done to prove it was not being caused by gluten if you could point me in the right direction, I’d appreciate it.