PySide6 Slow UTF-8 Display

I have QTableWidget 
When I set some text into it (about 10 rows only) .. the GUI gets frozen for 1-2 second

But  in PySide2  V: 5.15.2

It works perfect with no delay 
The problem appear only when try to display UTF-8 text

I also tried it in ubuntu v 20.04 in same version  PySide6 V 6.0.3

Also works perfect

So the problem only appear in Windows 10 v1909 and PySide 6.0.3

Any way to solve it ?
This problem appears (at least for me) on QTableWidget And QLineEdit And QPushButton
( I believe the problem with how PySide6 deal with UTF-8 text)

And it just happen on the first time 
So if I need later to display another UTF-8 text (in the same process) it display fast 
-There is a test file in the attachment