I stumbled across this bug when opening up an old project in AE 22 where my stacked Grid effects were no longer functioning correctly.
Version number: 22.6.0
OS: Windows 10 Pro
Also, changing GPU acceleration on/off doesn't change the result.
Steps to reproduce
1. Create a 1920x1080 25fps composition
2. Create a solid that matches comp size
3. Apply Grid effect, set the Size From to Width Slider, set Width to 100, and set Border to 8
4. Change the Grid Blending Mode to None
5. Duplicate the Grid effect and change the Width to 50, and set Border to 4
6. Change the Grid 2 effect Blending Mode to Normal
Expected Behaviour: Both Grid effects should be visible.
Actual Result: 2nd Grid effect completely erases the 1st.
See attached project & screenshots.