Earlier quoted context omitted.
Temporary and mild authoritarian measures during a once-in-a-century pandemic make complete sense, even to very libertarian people. The U.S. has a track record of such measures being temporary, such as the much more extreme measures taken during WW2. Comparing this kind of thing to what China is doing is drawing a false equivalency. There is no legitimate comparison to be made.
Which libertarians are you talking to? Every libertarian I've read or heard from has been against these " [t]emporary and mild authoritarian measures". The more popular libertarian publication/website, "Reason" has been against (all?) these measures.
Most Libertarians are extremist libertarians in my view.