Editable QComboBox changes currentIndex when all text is selected

I have an editable QComboBox box and connected the lineEdit::returnPressed()-Signal to a slot that appends the currentText() to a QTextEdit log.

Now the following happens:

1. Input "111" and press key return -> "111" appears in the log (Ok)
2. Input "222" and press key return -> "222" appears in the log (Ok)
3. Press key LineUp, to choose "111" again, press Ctrl+A to select all text, press key return -> "222" appears in the log (Wrong: expcted "111"). Also, the combo box now contains "222"

I found this because I wanted to always selectAll() text after Enter is pressed to ease the next input.