Mullvad is a bad choice for this particular case because they publish all their IPs, which makes them very easy to block. You should look into VPN providers that do not publish their IPs and that have a wide range of IP classes and multiple ASNs, which look like ordinary networks not associated with VPNs. In my experience, NordVPN and ExpressVPN have many of these.

Express and Nord are completely useless in China. Mullvad worked fine two years ago but is getting worse, not sure if it still works currently.