This is enforced by the service ( termsrv.dll ). This library handles the connection logic. To bypass this, administrators have been "patching" this DLL for decades to remove the concurrency check.
Replace with:
Marina, a senior sysadmin at a cash-strapped startup, stared at the “Remote Desktop Licensing mode is not configured” warning. Their Windows Server 2022 host was limited to two administrative RDP sessions. Three developers needed remote access for a weekend deployment. Buying RDS CALs would take days and cost more than her monthly coffee budget. termsrv.dll patch windows server 2022