Zwift login and play in China

I’m playing Zwift in China.
But, sometimes occurred error as “this account can’t login” or “login succeed but no road playable”.
some people have same problem.
But, in my case, I can login normally in daytime. The error occurred only at night.
Maybe it would be caused by Server issue.
is there any solution?

My guess is the ISP is blocking ports or access at certain time of the day.

On another subject, I would recommend you change your user name. Having your email address posted on a public forum is not a good idea.