"users report a black screen after they enter their credentials and system starts to load" - if you referring to horizon client login...
I think i might remember this issue a while ago with linked clones and dhcp, anyway check IP assigned to virtual desktop with blank screen and compare to dns record, i think i changed dhcp to register and manage dns records to remedy this in VDI subnet.
Some of the linked clones remain powered off after refresh, few days later another linked clone gets powered and gets same IP that previous had.
So ends up with few same IP's going to different host name.
But i'm not 100% sure because it works now with no issues.and have not deal with it for over a year