In my Excel application I have an Igrid which user can select an department. But on an 24 inch screen it looks like "normal" but on an 27 inch screen the view of the Igrid is not the same. I inserted 2 pictures which show the difference. Is there an option or settings which I forgot so the user of an 27 inch screen looks the same as on an 24 inch screen??

It looks like your two monitors have different dpi values. Most likely, one of them is a high-res 4K screen. If so, you need to process this situation in code and set the grid properties accordingly.

For example, if you use fixed column widths in pixels, they must be multiplied by the display scale factor. An alternative solution is using auto-width for columns, but all this depends on how you set up your iGrid.