mstsc stuck waiting for connection after connection reset by peer in logs

[IAmParadox27]

2024/10/02 10:43:28 Identity SessionId: {Session ID}, UserName: : Authenticated: false
2024/10/02 10:43:28 Client handshakeRequest from {Connecting IP}
2024/10/02 10:43:28 major: 1, minor: 0, version: 0, ext auth: 2
2024/10/02 10:43:28 Tunnel create
2024/10/02 10:43:28 Tunnel auth
2024/10/02 10:43:28 Channel create
2024/10/02 10:43:28 Verifying {Remote PC}:3389 host connection
2024/10/02 10:43:28 Checking host for user {User GUID}
2024/10/02 10:43:28 Establishing connection to RDP server: {Remote PC IP}:3389
2024/10/02 10:43:28 Connection established
2024/10/02 10:43:28 Error reading from local conn read tcp {Docker Instance of rdpgw IP}:40888->{Remote PC IP}:3389: read: connection reset by peer

I've omitted IP addresses throughout

I've got a setup where the https://gateway/connect?host={Remote IP}:3389 is authenticating against keycloak OpenID successfully and downloading an rdp file. When running that file it fails to get past "Connecting Remote Session". I've tried the suggestion from the other issue by setting EnableUserToken: false but this isn't working.

When I use the same flow on my iOS device, the RD Client app successfully establishes the connection and opens the RDP instance. Issue seems related to mstsc