Try it. Reduce the tokens to single characters but keep the structure. Does it work? Maybe single characters looks too much like an abbreviation and that throws

Try it. Reduce the tokens to single characters but keep the structure. Does it work? Maybe single characters looks too much like an abbreviation and that throws it off, because those are found in sufficiently different contexts. Exchange to two characters, three. Throw similar inputs at it and find the point where it reliably "gets it".