I don't think it's ever been correct to say the HK government was elected. It had some elected elements, but they were never in the majority: https://en.wikipedia.org/wiki/Legislative_Council_of_Hong_Ko....
IIRC, one of the five protest demands was for a fully elected government.
IIRC, they're structured so Bejing's allies would control those seats, with few exceptions (https://en.wikipedia.org/wiki/Education_(constituency)). I think most of the "voters" are representatives of industry associations and the like.
HK government was never elected. Beijing was always pulling strings from behind
This wasn't case in later stages of the protest, or even early stages. The protestors were gambling against Beijing in the first place, since they clearly didn't trust the local governance nor its ability to meet their demands. And it kinda made it obvious for the latter stage of the protest, that the attack was focus on CCP directly.
I mean we're talking about the same government on the bad side of the Tank Man photo. I think that's kind of obvious.
The difference is in HK I don't think people were anticipating China to completely break the Basic Law and the handover agreement. They were protesting the elected HK government, not Beijing directly.