That (Tractate 25) isn’t even discussing the portion of the Bread of Life discourse in John 6 where the concept of Transubstantiation is derived. So it’s disingenuous to apply it to the Dogma of Transubstantiation.
You should read from paragraph 15 of Tractate 26 onward. That would then truly be comparing apples to apples so to speak.
Learn to read! Verses 15 through 44 are covered here, and he quotes them explicitly. I know your faith in Catholicism blinds you to certain things, but do at least make the attempt.