How to reproduce:
1. Open the "ARDemo-Editing-AllWorldsBase_SHADOWTEST" Scene in the attached "LWRP_ShadowTest copy.zip" Unity project
2. In the Hierarchy window, locate the "Spot Light" GameObjects
3. Disable and enable the "Spot Light" GameObject in the "ARWorld1" GameObject's hierarchy
4. Repeat step 3 for the "Spot Light" in the "ARWorld2" GameObject hierarchy
5. Observe the geometry of the "ARWorld2" GameObject derive shadows from the "ARWorld1" GameObject geometry

Expected result: the "ARWorld2" GameObject should ignore the "ARWorld1" geometry when applying lighting
Actual result: the "ARWorld2" GameObject derives shadows from the "ARWorld1" GameObject and the shadows flicker when moving the Scene camera

Reproducible with: LWRP 6.9.2 (Unity 2019.2.14f1), 7.0.1 (Unity 2019.3.0b4)
Not reproducible with: LWRP 5.16.1 (Unity 2019.2.0b1), 6.5.3 (Unity 2019.2.0b1), 6.7.1 (Unity 2019.2.0b1)
Could not test with: LWRP 5.2.3 (Unity 2019.2.0b1)