Depending on what you were trying to watch, the limit can be 1, 2, 3, 4, 5, or 6 devices.
For Family Sharing, if you have that, it will be all users in the group combined. You may need to ask them too, to cut down on simultaneous streaming on multiple devices.
Check your Apple ID device list to find where you're signed in - Apple Support. You can soft sign out from other devices from your iPhone, just to make sure other devices are not counted for this limit. Perhaps you’ll see a device in the list that you didn’t consider before.
When after that “Remove from account” action, any of those other devices want access to settings or content that requires authentication, then it will prompt to sign in again. Nothing is lost from it.