How to reproduce:
1. Open the attached "Repro1190458.zip" Project
2. Build and run the Project
3. Logcat the device
4. Search for "QuitWorking" keywords in the log file

Expected behaviour: The "QuitWorking" keyword is found in the logs
Actual behaviour: The keyword is not found indicating that the Callbacks do not respond to Application.Unload()

Reproducible with: 2019.3.0a4, 2019.3.0b7, 2020.1.0a8
Not Reproducible with: 2017.4.33f1, 2018.4.11f1, 2019.2.9f1, 2019.3.0a3

Tested Devices:
VLNQA00115, Sony Xperia Z3 (D6603), Android 6.0.1, CPU: Snapdragon 801 MSM8974AC, GPU: Adreno (TM) 330
VLNQA00078, Motorola Nexus 6 (Nexus 6), Android 7.1.1, CPU: Snapdragon 805 APQ8084AB, GPU: Adreno (TM) 420
VLNQA00033, Samsung Galaxy Nexus (Galaxy Nexus), Android 4.3, CPU: TI OMAP 4460, GPU: PowerVR SGX 540

Note: could not reproduce with iPad Mini 2 iOS 12.0.1. On 2020.1.0a8 device opened up, but did not Unload, after touching the screen it crashed. In the documentation, it does not say that Application.Unload() works with IOS, but if you try to use Application.Unload() in editor it tells you to use either Android or IOS device as only these platforms support this method.