nah, after I reply this, things happen again.
but! now it is being gone after it flashing once shortly.
way better than before that continuosly flashing when it start.
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I found weird solution for this while trying to solve..
this happen only with colored mouse cursor... especially cyan or magenta which I used normally over few years.
(don't know about other custom color could cause this)
now I'm testing with inverted cursor which is mostly shown white or black caused by dark theme on whole system.
mouse cursor size were same as previously what I used to set to '5' on windows 11 settings.
there is no more screen flashing yet after changing cursor color/type.. over 3 days now..
Let me try week or more for test.