I can't seem to re-create the issue. I followed the guide again (just to make sure) and it works as expected.
You can Download a test project I made up until figure 7 & 8. Not exactly sure what's going on? O_o
Create another default background layer under your BackFloor can solve it.
The same thing....
Beta
IDE v23.1.1.306
Runtime v23.1.1.305
