To reproduce:

1. Download attached "SystemGroupDepthTest.zip" project and open in Unity
2. Open "TestScene" scene
3. Enter to Play Mode
4. Open EntityDebugger
5. Check "Show Inactive System" and look for SystemOne and SystemThree

Expected results: SystemOne and SystemThree are active and both display the list of components they iterate over
Actual results: SystemOne and SystemThree aren't active and both cannot display the list of components they iterate over

Notes:
- Could not check for Regression on Unity 2018.4 and lower because the Project becomes Corrupted
- Could not check for Package Regression on preview.33 - 0.0.12 and lower because the Project becomes Corrupted
- When the SystemTwo is in UpdateInGroup(typeof(GroupLevelOneHalfTick)) and SystemFour is in UpdateInGroup(typeof(GroupLevelTwoHalfTick)), both Systems do not work
- Images for Reference are attached in the Comments section

Reproduced on Package preview - 0.1.1 and preview - 0.1.0

Reproduced on 2019.2.4f1, 2019.3.0b2 and 2020.1.0a3