@fizzylemon50 The testing you've had sounds very thorough, and you sound very knowledgeable. You didn't mention genetic testing (or I missed it). If you didn't have human leukocyte antigens (HLA-DQ2 and HLA-DQ8) then that would rule out celiac (almost certainly, from what I understand).

Have you had genetic testing?
https://www.mayoclinic.org/diseases-conditions/celiac-disease/diagnosis-treatment/drc-20352225