I have gone to Connections and disconnected from Strava and then connected again. This does not solve the problem. When I click connect the next page gives me a button to Authorize. When I click authorize it takes me to a page showing my recent activities. I would think that I would at some point in connecting to Strava I would have to enter my Strava log in information but it doesn’t ask. If I go back to the connections page it will now give me the option of disconnecting from Strava which would indicate that I am connected. Unfortunately my activities won’t upload. I have gone through this process several times.
It sounds like your Connections page is using information left in your browser cache to recreate the connection without asking for your account credentials. Try disconnecting Strava one more time, but afterward, completely log out of your account on our website, close your web browser, then reopen it, log back into Zwift and visit your connection’s page, and try to connect Strava again. That should trigger the connection to ask for your Strava account credentials and force Zwift into re-authorizing with their server.
https://my.zwift.com/profile/connections
If that still doesn’t seem to help, please let me know. At that point, I’d like to create an email support ticket for you so we can ask for copies of your log files to research.
Let me know how it goes!