Dialogs are only drawn after the execution finishes, but only in some installations

I have this problem just on some windows machines, which for all I can say are identical OS and python environment.

Version of prompt_toolkit is 3.0.18
Python is winpython: Python 3.9.4 (tags/v3.9.4:1f2e308, Apr 6 2021, 13:40:21) [MSC v.1928 64 bit (AMD64)] on win32
Windows 10 Enterprise LTSC 64Bit

This is the minimal example I wrote in test.py to "reproduce" this.

from prompt_toolkit.shortcuts import message_dialog
message_dialog(title="minimal", text="sample").run()

On most machines this works as expected, but in some others the terminal is completely blank, except the cursor at the top left corner.

Once I press enter, the expected dialog is drawn (after the program is already closed).

On the non-working machines the problem is reproducible in both cmd.exe and PowerShell terminal.

Start by running the minimal test.py example in both cmd.exe and PowerShell on the affected Windows installations, using the reported Python and prompt_toolkit versions. Compare the blank terminal behavior with a working machine and trace the dialog rendering path. Done means the dialog is drawn before execution finishes on the affected terminals, with a regression check if the project has a suitable test location.