The sticking point is what the words “transubstantiation” “actually being” mean.
Materialistic Westerners who believe in SCIENCE!™ have the mistaken impression that the words mean “magically transformed, to be chemically identical to”.
But, speaking of science, just as science uses everyday words but gives them a specific meaning within the context of scientific disciple (e.g. the word “force” means a scalar quantity mass multiplied by a vector quantity, acceleration, instead of a verb meaning “to compel”), the words “transubstantiation” are applied within the context of Aristotelean “accidents” and “substances” (these also being words specially defined within a disciple to mean something other than the vernacular).