fix(chattextedit): ChatTextEdit bug fix for issue #5020 Corrected

src/widget/tool/chattextedit.cpp

@@ -58,7 +58,7 @@ void ChatTextEdit::keyPressEvent(QKeyEvent* event)
         return;
     }
     if (key == Qt::Key_Up && this->toPlainText().isEmpty()) {
-        this->setText(lastMessage);
+        this->setPlainText(lastMessage);
         this->setFocus();
         this->moveCursor(QTextCursor::MoveOperation::End, QTextCursor::MoveMode::MoveAnchor);
         return;