Yes, maybe it's a bug of the newest GMS23
Solved through your code.
TKS!
And can create another default background layer under your BackFloor to solve this issue as same as you.
Okay cool. Well I just tried it (see other comment) and I couldn't seem to re-create the issue. I'm running GM:
IDE v2.3.2.560
Runtime v2.3.2.426
Haven't tried it with the BETA though. Glad it was solved! :D