There are different privacy settings for your profile and for your activities. It sounds like you set the default activity privacy to followers, but I think you want to set your profile privacy to approve follow requests:
Thanks! The slider «Approve Follow Requests» are set, but the problem is to remove/block any user that are following you before the slider is set or afterwards. Time for Zwift to create «block user» function right-of-way !
Yes. You can do that in the Companion app. Open the list of your followers, select the name of the person. When their profile opens, tap the 3 dots in the upper right, then select ‘Remove Follower’ from the option list. You can also report the user from this list.