[GoinAllTheWay]

Originally Posted by taxbuster

Definitely temporarily turn off all the Windows (and any other) software firewalls in your debugging. No firewall setting in your Unifi (or other router) should interfere internally - other than providing IP connection, there shouldn't be any router function.

I tried turning off the firewall on the target PC, should I do the same on the PC I'm trying to connect from?

Assume you're not crossing from one VLAN to another? (Do you have VLANs?)

No, no VLAN's at all

And, just for testing, do you have a spare router you can dummy up a quick network in, connect both machines and try RDP? Might be instructive.

Actually yes, I do. I have my old edgerouter. May need to wait for a long weekend as I don't want to mess up our network with wife WFH full time and me every other week.

And a curiosity: have you tried accessing the machine remotely from "outside" your network, with port-forwarding temporarily enabled to that machine/IP?
No, that's getting a bit beyond my skills.

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