Websites that use
Website.user_vars property in versions.
It affects versions v2.0.1 to v2.4.0. Please upgrade to v2.4.1
Do not use
Website.user_vars in websites when using versions v2.0.1 to v2.4.0. Also, do not use
Website.signin_user() in version v2.4.0 only.
ToUI is using Flask-Caching (SimpleCache) to store user variables. My misunderstanding was that these caches are stored in the client's browser, but it seems that these are stored in the server side.