How to reproduce:
1. Create a new project
2. Open the Build Settings (File -> Build Settings)
3. Enable these settings: Server Build, Development Build, Script Debugging
4. Click 'Build and Run'

Expected result: the Player console displays the Managed Debugger port number and waits for user input before running the Scripts (to give the user as much time as needed to attach the Debugger)
Actual result: a 10-second countdown begins before the Scripts are run and the port number is displayed

Reproducible with: 2018.4.27f1, 2019.4.9f1, 2020.1.4f1, 2020.2.0b1

Notes:
1. When enabling the 'Wait for Managed Debugger' setting, there's still a 10-second countdown before the port is displayed
2. The countdown takes only 3 seconds in the 2018.4 stream