As reported by Michael de Raadt in MDL-27916:

I'm still not sure the feedback on adaptive questions is consistent and correct.

I tried a three-question adaptive quiz to test MDLQA-1095. For the first two questions, after answering incorrectly then correctly, I got the response I expected.

Marks for this submission: 1.00/1.00. With previous penalties this gives 0.90/1.00. This submission attracted a penalty of 0.1000000.

On the third and final question (a true/false question) I received the following feedback.

Marks for this submission: 1.00/1.00. With previous penalties this gives 0.00/1.00. This submission attracted a penalty of 1.0000000.

And when I was shown the summary at the end of the quiz, all questions were shown as receiving 0.90 marks. So I believe it is calculating the marks correctly, but this final piece of question feedback was incorrect.

This incorrect feedback was also shown during the quiz review.

Also reported by moronke Fajobi in MDLQA-1095:

i do not see any differenc in setting the quiz to adaptive mode with penalties or adaptive mode without penalties.

when it was set to adaptive mode with penalties, no deduction was made from the student's score.