I did some testing and was unable to replicate your problem. I created a file upload assignment, a text box assignment, and a quiz, and I enabled a missing policy where students got 0% if they missed the assignment due date. I duly saw the missing label and zero points for a student who missed the assignments, but when the student submitted something to the box assignment the label changed to late. When I manually typed in a score for the quiz, the label disappeared.
Because Canvas is not behaving as expected for you, the best option is to report this bug via the Help menu in your Canvas instance. That will get it to your local Canvas support team or IT help desk. It would be great if their vigilance extended to the Canvas Question Forum, alas it does not.
I’m going to mark this reply as a solution. I realize it does not solve your problem, but our colleagues who encounter a similar challenge will also find the best place to go for help.