Dragging files to subfolders

[Horst.Epp]

I can't confirm. On F5, this should not affect at all, only holding the LMB.

I hit F5 function key using the mouse, that's my normal behavior.

[Fla$her]

I hit F5 function key using the mouse, that's my normal behavior.

Oh, you mean the function key bar. In my case, it was always disabled as unnecessary.
Apparently, the option of auto-moving the cursor to the OK button is enabled in your system.