Hi,
I have a use case where the cell background should be set to certain color with an opacity less than 1. In this case I discovered that these cells don't get covered by the fixed rows (top and bottom) as you can see in the attached screenshot.
You can reproduce the bug with this project (https://drive.google.com/file/d/10XpXzlycl0Bmj3SwB6F5I8bTzSiHu6Pi/view?usp=sharing)
If you set the opacity to FF or remove it completely, then it works.
onBeforeCellRender: (args) => {
args.cell.backColor = '#D3D3D366';
},
Best regards