I created a quiz exactly as normal, then previewed it and realised that the answers in the quiz had been autolinked to my main glossary. I went into activity filters and chose autolink-off. I cleared the caches and my browser cache then went back to the quiz. Autolinking was still active. I did nothing unusual in creating the quiz. Obviously, this renders it very difficult to create quizzes if they involve testing on concepts added to the glossary.
This defective filter wouldn't be so important if it were possible to use prevent autolinking (at individual question level) on the quiz answers (it can be selected on questions, not answers).