JTextField select complete text on focus

[Rdiger-36]

Hi,
I'm not sure if it's my mistake or how I use it, but when I load my GUI application and set the JFrame visible, I want to focus a JTextField. This text field contains a prefix of 7 characters. When the frame becomes visible and I set focus to the text field, I want the caret to be positioned right after the prefix.
This works fine with all other Look and Feels, but not with FlatLaf themes.

My Code:

JTextFiled txt = new JTextField("PCTEST-");
txt.setCarretPosition(7);

I am limited by Java 8 (build 1.8.0_432-b06).
OS: Windows 11 23H2
FlatLaf Version 3.5.4