Awarding partial credit for drag & drop question by combining freeform drag & drop slide with MC question

Hi everyone, I've only recently started working with Storyline 360 and have tried out a number of the suggestions in the discussions about awarding partial credit. Sadly I have not found a complete solution yet and would be really grateful for some help if you have time. I have built a freeform drag & drop question with six drag items and six drop targets. To enable partial scoring I have followed these instructions ihttps://www.youtube.com/watch?v=gFKFrfM4BUU and copied & pasted my freeform drag & drop slide onto an MC slide. I've set up all the variables as instructed in the video, but have the following two problems: 1) although my freeform drag & drop slide on its own works fine, my combined drag & drop-MC slide will only allow me to enter correct answers: when I drag and drop an item to an incorrect drop target it automatically bounces back to its start location. 2) when I repeatedly add a correct answer to its drop target the variable counter keeps adding another point for answering correctly, so that I can also achieve the maximum of 6 by dragging and dropping the same answer to its correct drop target 6 times (this is relevant if the user hesitates and moves answers around before submitting). Does anyone have any advice for how to get around these two problems? Otherwise the suggested solution and the slide look great, so if possible I'd really like to get it to work correctly🙂 Many thanks!