How to reproduce:
1. Open the “SmallRiderMPPM“ project
2. Open the “SampleScene“
3. Set the “Edit/Project Settings/Editor/Enter Play Mode Settings“ to Do not reload Domain
4. Navigate to “Unity/Settings/External Tools“ and set External Script Editor to Rider IDE
5. Open the “Windows/Multiplayer/Multiplayer Play Mode“ window
6. Activate the “Player 2“ Virtual Player
7. Enter and exit the Play Mode
8. Open the “TestScript.cs“ in the Rider IDE
9. Change the 9th line to “Debug.Log(“A“);“ save the changes
10. Enter the Play Mode

Expected result: The “Main Editor“ and the “Player 2“ are logging “A“
Actual result: The “Main Editor“ is logging “A“, but the “Player 2“ is logging “B“

Reproducible with: 1.2.2, 1.3.0-pre.1, 1.3.0-pre.2 (6000.0.19f1)
Could not test with: 2021.3.43f1, 2022.3.46f1 (“com.unity.multiplayer.playmode” not supported)

Reproducible on: macOS 14.5 (Intel), Windows 10 Pro (22H2)
Not reproducible on: No other environments tested

Workaround: Before entering the Play Mode manually reactivate the “Player 2“ (the secondary Player)

Note:
- More information in the comments
- Does not reproduce with Visual Studio Code and Visual Studio, only with the Jetbrains Rider IDE