After recent two Android security updates, Samsung Galaxy Note 8 plugged into a DeX station is unable to detect it and therefore it is not offering the notification which allows to turn on the external monitor or going to DeX options.
Attached keyboard and mouse via USB ports on Dex Station still work fine with the phone as it is. Only the DeX mode recognition seems to be gone.
What I did try:
An advice to plug the phone into DeX Station unplugged from the power and the re-attached the power cable but it did not help the DeX recognition.
A troubleshooter from Samsung. Update was completed, no change.