Update: Samsung just released new drivers (1.6.6) which resolve the issue.
Samsung T5 driver does not work on latest MacOS. The amount of anger and frustration in this support thread is quite justifiable.
It is un accepted that a company which sells SSD does not bother updating their driver. Mac Beta program is very clear and allows enough time for vendor to modify and qualify their products, but it seems Samsung did not bother doing it.
As the thread mentions there are workarounds and it works for me, but I still think this is a very bad customer experience.