Hello! - I'm a designer working on this course with Chris.
When selecting an answer in the matching question component, the dropdown doesn't remain open, and closely immediately. We are testing on iPhone 7 iOS 12.3.1 mobile Safari/Chrome, I have a test case here: http://www.jseangeary.com/usss/matching-test/index.html
I have had a successful test upgrading my local AT to v081/v241 (I was running v080/v240 still causing the mobile issue).
I'm not sure what was causing the issue, but that last upgrade seems to have solved it???