I have my opinion on gluten intolerance but that’s not the point here. The point is that Huel is gluten free even in the normal version. It’s like thinking to have a problem with lactose eating something lactose free.
I gave a not accurate explanation in the post before due to a memory fault, sorry, but the basic idea is the same. Here’s a clarification:
If you have issues with that tiny percentage, then you have probably a severe form of celiac disease. There are appropriate diagnostic exams for that (my sister had that tested because she had a recurrent diarrhea for a period. But no, it wasn’t the case, luckily). Otherwise, I would exclude that as a cause unless any other cause is excluded. 