The source is literally in your link. Read it carefully.
residents polled in a survey conducted **for Reuters** by the Hong Kong Public Opinion Research Institute
It's literally commission by Reuters, a British news agency. It isn't academic malpractice because the institute was no longer part of HKU. Further more, their chief executive was accused of treason and has historically expressed anti-Beijing, pro-succession ideas. Clearly this institution was not going to be unbiased.
Anyways, how was your experience living in Hong Kong in 2019?
Anyways, how was your experience living in Hong Kong in 2019?