Sorry, the original working XML code I am trying to test duplicate works between list and plain text .
However, even after modifying your lambda to plain text I get a same error - compiler does not like the "copy to" function.

Qt Code: 
  1. QObject::connect(ui->list,        //object
  2.     &QListWidget::itemClicked,      //signal
  3.     [this]( QPlainTextEdit * pItem ) { this->ui->plainTextEdit->appendPlainText( pItem ); }) ; // lambda slot
  4.  //   [this]( QListWidgetItem * pItem ) { this->ui->list_2->addItem( pItem ); }) ; // lambda slot
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Qt Code: 
  1. /media/f/QT/Qt/QT/qtconnectivity/examples/bluetooth/CAT_BT_18112020/device.cpp:154: error: no matching function for call to 'QPlainTextEdit::appendPlainText(QPlainTextEdit*&)'
  2.      [this]( QPlainTextEdit * pItem ) { this->ui->plainTextEdit->appendPlainText( pItem ); }) ; // lambda slot
  3.                                                                                         ^
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