If you do something in a tab in a private window, it will do the same in all the tabs in the window and at worst.
-Reload tabs → All tabs in the private window will be reloaded.
-Scale the hop-up window → It is not scaled, and another tab is scaled for some reason.
-Close one specific private window out of multiple → All private windows are closed.
OS: Windows 10 Pro 21H1 (64bit) (Build number: 10.0.19043.151)
Ver. 3.5. * ～ 4.1.2369.11