I am not sure if it's an error...it could be an error from IRCC. I'd check with them.
The trips they want information do check out (quick trips to the USA by land in 2015 and 2016), and I did travel to Asia in 2016, but not Hong Kong. I do not know if the specific dynamics between mainland China and Hong Kong may be part of the issue....
I am trying to track down all my flight itineraries and tickets to respond to all of their requests (including flights and travel outside my eligibility period because they are unable to read some stamps from 10 years ago), and I will definitely try calling them this week, you know... hoping they actually take my call. Webform is not an option as I need to submit everything in a few weeks and webform takes forever.
The only silver lining is that language requirements and prohibitions were updated to "Completed", physical presence still in progress because of this...