Application.screenupdating=false don't work properly in Microsoft 365

I developed a professional application in Excel wich I bring to the market soon. It has 7 sheets and 58.000 VBA codelines.

Ofcourse I use the application.screenupdating=false comment at the start of a subrouting to speedup things. At the office we use Excel 2016  and there is no problem at all, but at home I use Microsoft 365 and there it doesn't work properly. The screen flickers allthough I use this command. Maybe using an addin or other sollution instead of the screenupdating-command? But better would be that Microsft solves this problem!

Any Thoughts wat a sollution can be?

I read this problem on several forums, but Microsoft hasn't solved this until today!

PLEASE SOLVE THIS PROBLEM MICROSOFT!