Old news Fuzzy. This has been happing on the premier + and Ultra since they were launched.
The easy way to get the 4K row back (it's a PITA though, because you have to do it every time...)
Scroll up to the "Gear" (settings) go to "Get help" then click on "restart Netflix"
when Netflix re-launches, your 4K/HDR content will display as long as you have a 4K account with Netflix.
The DISGUSTING part is the fact that ROKU has known about this issue since November since the Ultra launched and have failed to do anything about it.
I have called several times, all I get is excuses.
Samsung UN65JS8500 (4K/HDR)
Yamaha RX-A770 Aventage AVR
Yamaha RX-V679 AVR