"Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo" is a grammatically correct sentence in English that is often presented as an example of how homonyms and homophones can be used to create complicated linguistic constructs through lexical ambiguity.
No it isn't. Language should convey its own meaning. If you need a whole page of diagrams and supplementary materials to explain your sentence then it was never a sentence to start with. "Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo" may be a joke or a riddle but it is in no way a grammatically correct sentence.
There are tons of examples of things that are grammatically correct, but also ambiguous enough to need external explanation.
At best you could say it’s a poor choice of words if you’re actually trying to convey something to your readers, but it most definitely is grammatically correct, as evidenced by the page of diagrams and supplementary materials that explained exactly why.