Why do my labels go blue when switching notebook tabs

[shartrec (Trevor Campbell)]

In my application Gtk-Rust, I have a GTKNotebook container, with three children, each having a TreeView and below the treeview, a GtkLabel, GtkEntry and GtkButton. When I run the app, as I switch pages the GtkLabel, gets highlighted in blue sometimes. The Entry and button also get selection highlights randomly. See img below

Why does this happen? and how can I prevent it?
I am using CompositeTemplates for the UI.

[shartrec (Trevor Campbell)]

I found the problem. I had the three widgets in a FlowBox and this adds FlowBoxChild containers around each widget that causes this strange behaviour. Using Box instead solves the problem

[gwillems]

Probably it’s because The FlowBox selects its first element when it gets the focus, which appears then blue.

Maybe try to set the FlowBox “selection-mode” property to NONE.