How to reproduce:
1. Extract and open the attached “IN-135060.zip“ project
2. Select File → Build And Run
3. Run the project for ~10 seconds
4. Close the built Project
5. Open Player.log
6. Observe the error messages in the log

Actual result: “NotSupportedException: The URI prefix is not recognized.” error messages are spammed in the Player.log
Expected result: The “System.Net.HttpWebResponse len -1“ message is logged in the Player.log

Reproducible with: 2023.3.0b4, 6000.0.69f1, 6000.3.10f1, 6000.4.0b11, 6000.5.0a8
Not reproducible with: 2023.3.0b3

Reproducible on: Ubuntu 22.04 (Build for LinuxStandalone), Windows 11 (Build for Windows Dedicated Server, tested by the user)
Could not reproduce on: No other environment tested

Workaround: After the build, NetworkBugProject\NetworkBug_Data\MonoBleedingEdge\etc\mono folder seems to be missing the 4.5 folder. Importing a 4.5 folder from a working project to NetworkBugProject\NetworkBug_Data\MonoBleedingEdge\etc\mono fixes the issue.

Note: If the error is not present in Player.log, also check out Player-prev.log