Scroll Area is affected by zoom level?

[KX13ZN]

I have a number of scroll areas set in my workbook.open module.

All bar 2 or them work as intended.

Both of the sheets that don't work are not working in exactly the same way.

Depending on the zoom level, if the outer boundary of the scroll area is set beyond the current view then scrolling is limited as expected.

eg at 100% zoom the viewable range is A1:AE39. if I set a scroll area outside of this say A1:AE40, it works as expected.

if i set a scroll area inside the view range then the sheet scrolls until the last used row is out of view.

the code im using in workbook.open;

Sheets("PDASH").ScrollArea = "A1:Q36"

The sheet properties show the scroll area set properly as $A$1:$Q$36

at 100% zoom i can scroll to row 53
at 110% zoom i can scroll to row 50
at 130% zoom i can scroll to row 44
at 150% zoom i can scroll to row 39
at 170% zoom i can scroll to row 36

I have no idea why the scroll area only works properly at 170% zoom

I have no idea why its being this way and only on 2 sheets?

Can anyone shed light on this?