QtCreator crashes after rename QPushButton in Designer

Since the new QtCreator 6 I faced the following issue:

If I rename a QPushButton in the Designer the QtCreator crashes sporadically. Sometimes I can reproduce this by doing the following:

• create a new project
• add 3 QPushButtons
• rename them one by one
• DON'T press enter after renaming the buttons but click with the mouse somewhere outside of the edit field
• after about 4 or 5 times of renaming different buttons the QtCreator crashes

This is not happening if I close the editing by hitting the enter button or when I rename other widgets.

I attached a small video what happend if I rename the buttons.