Standalone Player becomes unresponsive before closing when using Alt+F4 under a DNS black-hole configuration

Steps to reproduce:

1. Open a terminal in the attached “IN-152792“ project folder and run:
   python .\repro-scripts\dns_sink.py
2. Leave the DNS sink running and open another terminal
3. Find the active network interface and note its InterfaceIndex and current ServerAddresses:
   Get-DnsClientServerAddress -AddressFamily IPv4 | Where-Object ServerAddresses | Format-Table InterfaceIndex,InterfaceAlias,ServerAddresses
4. Open PowerShell as Administrator, replace <N> with the interface index from step 3, and run:
   Set-DnsClientServerAddress -InterfaceIndex <N> -ServerAddresses 127.0.0.1
   ipconfig /flushdns
5. Verify the DNS configuration:
   {{(Measure-Command { Resolve-DnsName unity.com -ErrorAction SilentlyContinue }

   ).TotalSeconds}}
   {{(Measure-Command

   { Resolve-DnsName dns-sink.test -ErrorAction SilentlyContinue }

   ).TotalSeconds}}

6. Confirm that unity.com resolves in under one second and dns-sink.test takes approximately 10 seconds
7. If the DNS sink stopped during verification, start it again:
   python .\repro-scripts\dns_sink.py
8. Run Build/3488607 - Freeze on quit build.exe
9. Wait approximately 10 seconds
10. Close the Player using Alt+F4
11. Observe the Player window

Actual result: The Player becomes unresponsive and remains open from 2 to 10 seconds before closing
Expected result: The Player closes immediately

Reproducible with: 6000.0.0f1, 6000.0.83f1, 6000.3.24f1, 6000.6.1f1, 6000.7.0a6

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Notes:

• The delay may range from a few seconds in the reproduction project to over one minute in the customer’s project
• The issue is associated with slow or unavailable DNS resolution during Player cleanup
• The customer’s dump indicates that the main thread waits in UnityWebRequestManager::Cleanup while a request to https://cdp.cloud.unity3d.com/v1/events is resolving
• The customer reported that removing the Analytics package prevents the longer freeze. However, a shorter delay was also observed in a blank project without Analytics
• Restore the network configuration after testing by running the following in Administrator PowerShell, replacing <N> with the interface index:
  Set-DnsClientServerAddress -InterfaceIndex <N> -ResetServerAddresses
  ipconfig /flushdns