Hello Meir,
You can write a macro (it can be a dummy macro, for example just one comment line)
//
and then associate to the “Scrolled” event. (Macros menu > Customize > select the macro name you created, click “Runs at Events”, click “Events…” button, and check “Scrolled”, and select Delay Time 0.
When a macro is finished running, EmEditor automatically redraws the whole window.
Thanks!