UnityWebRequest TLS handshake problem during HTTPS SSL connection to Windows Server 2012 R2 when in Play Mode

Reproduction steps:

1. Open the user’s attached project (“UnityWebRequestTLS12.zip”)
2. Enter the Play Mode

Expected result: Editor establishes HTTPS / SSL connection to Windows server 2012 R2
Actual result: The Game window displays the text "unable to complete ssl connection"

Reproducible with: 2020.3.40f1, 2021.3.11f1, 2022.1.19f1, 2022.2.0b9, 2023.1.0a13

Reproduced on: Windows 10 Pro 21H2

Notes:

• see handshake problems in Windows's system log:
  "An TLS 1.2 connection request was received from a remote client application, but none of the cipher suites supported by the client application are supported by the server. The SSL connection request has failed."
  and
  "A fatal alert was generated and sent to the remote endpoint. This may result in termination of the connection. The TLS protocol defined fatal error code is 40. The Windows SChannel error state is 1205."
• Unity 2019.4.38f1's UnityWebRequest everything was fine