thank you for giving me access to you Moodle site.
I tried the "Articles" HotPot, as a student - you can see my score of 100% was correctly recorded.
I tried the HotPot again and this time I answered a few questions, clicked the check button, and got a a message saying my score so far was 7% but that there were still unanswered questions. Then I deliberately clicked on the link at the top of the page to go back to the course page. I got the message asking whether to stay on the page or navigate away. I chose to navigate away. When I went back to look at my score for that attempt, it was 0% - not 7% as I might have hoped.
From this, I would say that it seems that the score is not recorded if you navigate away from the quiz before completing all the questions. You do not need to answer every question correctly first time, but any questions you do not answer correctly, you need to keep going until you do answer each question correctly. This is the way HotPots work.
The HotPot is only finished when all questions have been answered correctly. Only then are the results sent back to the server.
In the past, it was possible for the browser to send the results so far if the student tries to navigate away from the page before the HotPot was completed. Perhaps this functionality is broken now on some or all browsers. We could that that more.
However, I am pretty sure that if users complete the quiz, i.e. keep going until they find the correct answers to all the questions, then the grade will be recorded.