Canvas changing questions in quizzes on its own

[akay]

I have been experiencing odd behavior from Canvas creating quizzes.

In a recent 33 question quiz of numeric type questions, I have noted that Canvas will randomly change a number of the questions back to multiple choice type questions. 

When edits are made to the question to switch it back to numeric question type, question updated and quiz resaved, the quiz preview reveals nothing has changed.

When a duplicate question is created and the offending question is deleted, Canvas flips another question to a multiple choice type.

Anyone out there have any insights? I've expended enough time chasing this abhorrent "feature".