Running into an issue with Hyper-V guest 1709 system RDP Sessions

Sep 17, 2012
I'm running into an issue where RDPing into a system results in a new session being opened up.

Dual Xeon E5-2687v4 (2x12/24), 256GB DDR4, 2x Quadro P5000, 8x 1TB RAID0
Windows 10 1709 host

This was originally purchased as a workstation, but after storm damage ruined the motherboard, we ended up stripping the system, and upgrading the replacement workstation. This doubled the CPU count, RAM, SSD, and video count.

We set the system up to allow Hyper-V machines, allocating half the RAM, half the CPU thread count, I've got a 4x1TB RAID 0 dedicated to Hyper-V storage, and one of the P5000s is set for RemoteFX.

While performance with RemoteFX seems to be "adequate" for what they're doing, but we've run into something that's stopping us: when the user remotes into the machine via RDP, sets a program to start running (render jobs or something), they'll then disconnect (not log out).

When they try to reconnect, instead of their old session being logged into, they will start a new session. They can't reconnect to the old session, and they'll lose out on all the data that was being generated. The virtual machine has been known to have upwards of 8 sessions (6 disconnected) at one time, with their single active, and my admin account also active.

This issue does not happen when the Hyper-V machine is running 1703 as the guest OS.

This issue is not reproducible on physical or VMware based machines. It's just Hyper-V.

Online research talks about remote printers, but we don't have that enabled, so that's not it.
Have you watched the sessions while someone tries to log back on? Does it terminate the old sessions and create a new, or create a duplicate so you have one active one inactive for the same username?

Are these domain joined machines/accounts?

Any way to test with straight RDP to rule out a bug in RemoteFX? I haven't used rFX at all, so I can't give any input there.
Well, when I test it, I disconnect. When I go to reconnect, it drops me at the screen it shows when first logging in, like it's loading all the software for a login.

This is a domain joined setup.

I'll go double check on the RDP/RemoteFX thing by logging into a Hyper-V system that doesn't have RemoteFX. I'll have to get 1709 installed on a Hyper-V system running Windows 10, but that's not going to be too big a pain.
Shit. RemoteFX /1709 is the cause. No RemoteFX and 1709 works fine...but enable the card, and I can't reconnect to my sessions.

At least that narrows things down a bit. It's not a general RDP issue so much as it is this special unique snowflake of a system.

Maybe I should have just told them to spend money and get physical machines. But, this just cost time.