The Apple TV app on third party devices is supposed to save the last known user account for a next time — unless you sign out of the app, reset the app, or delete and reinstall the app.
This saving might be influenced by device privacy settings, e.g. not allowing any local storage for a particular app. Not sure how the system software of a Hisense TV handles that. If you can, check your TV settings.
Try deleting and reinstalling the app one more time to invoke any optional agreements that may apply for apps on this device.
Else contact the Apple Support staff for assistance or other suggestions. Contact Apple for support and service (phone numbers) or start your support request online (chat/email/callback).