Absolute minimal WMS implementation doesn't work - Dell unhelpful

I'm trying to implement WMS auto discovery as a proof of concept for automating updates for thin clients. 

All manual registration works as it should. 

Auto-discovery works on fresh merlin WTOS 8.6710 and upgraded 8.6807
Auto-discovery and network accessibility breaks when upgrading to 9.1 (manual registration works)

9.1 does not populate any information

8.6 populates all WMS information and can successfully auto-update to 9.1

 

My network is designed to be the absolute minimum

(1) is a dedicated Windows Server 2019 with *only* dhcp and dns installed (potentially misconfigured dns) (one domain and one addressing scope) (no active directory)

(2) is a dedicated Windows Server 2019 with *only* WMS installed (since WMS can't be on the same server for 9.1 for some reason?)

(3) is a Wyse 5070 Thin client running either a fresh merlin install of WTOS 8.710 or WTOS 9.1

 

(1) -> SWITCH -> (2),(3)

 

 

I had an earlier implementation that worked with 8.6

(1)-> (3)

But according to Dell that is "not normal" and "will not work" if "WMS and DHCP are on the same server"

So I tossed in a switch and made WMS it's own server - and auto-discovery still does not work

 

The tech support mentioned a tab called "Auto-Discovery" that is only available for the pro version

- is WTOS 9.1 auto-discovery disabled unless I buy it? 

 

I'll update as support helps me out, but since this is more than checkboxes within WMS I don't think I'll have much.

I'm hoping one of you sysadmin gurus can help me out.

Thanks!