The new system in Drafts 5 is much more flexible and consistent. The only service not using the new system is Evernote, the one you have trouble with, which is using the authentication process in the SDK Evernote provides - which I’ve had a lot of problems with over the years, especially related to Evernote China login. It’s been broken in Drafts 4 many times over the years, as well.
I’m sure we’ll sort out the issue soon. Once it app is out I’ll be able to get more data point from Chinese users and try to track down the issue.