Threads do not terminate when the main Window is closed

[kangz12345]

Describe the bug

When the main window of iquip is closed, the program does not quit even if all the windows are closed.
If I try to quit the process via Ctrl+C, a KeyboardInterrupt traceback message appears but not terminating.

Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\stage.py", line 435, in readAllPositions
    @pyqtSlot()

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\stage.py", line 466, in handlePositionReported
    @pyqtSlot(str, float)

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\monitor.py", line 1136, in _updateTTLStatus
    """Turns on or off the TTL switch, which controls the target DDS channel output

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\monitor.py", line 1136, in _updateTTLStatus
    """Turns on or off the TTL switch, which controls the target DDS channel output

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\monitor.py", line 1136, in _updateTTLStatus
    """Turns on or off the TTL switch, which controls the target DDS channel output

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\stage.py", line 435, in readAllPositions
    @pyqtSlot()

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\monitor.py", line 1136, in _updateTTLStatus
    """Turns on or off the TTL switch, which controls the target DDS channel output

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\stage.py", line 435, in readAllPositions
    @pyqtSlot()

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\stage.py", line 435, in readAllPositions
    @pyqtSlot()

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\stage.py", line 435, in readAllPositions
    @pyqtSlot()

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\monitor.py", line 1136, in _updateTTLStatus
    """Turns on or off the TTL switch, which controls the target DDS channel output

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\monitor.py", line 1136, in _updateTTLStatus
    """Turns on or off the TTL switch, which controls the target DDS channel output

KeyboardInterrupt
Traceback (most recent call last):
  File "C:\Users\QC109_3\iquip\iquip\apps\stage.py", line 435, in readAllPositions
    @pyqtSlot()

KeyboardInterrupt

Expected behavior

The process should terminate without leaving any threads alive.

To Reproduce

Not confirmed yet.