Font becomes unreadable in PopupMenu when using "display/window/stretch/scale"

Godot Version

4.2.2.stable.mono

Question

Hi to all! I encountered a problem using PopupMenu (OptionButton) when scaling the UI (display/window/stretch/scale in project settings), most likely it is related to using SubViewport, but I don’t know how to solve it.
I will be grateful to anyone who can help

video how it looks: