Surface Pro very small icons and menu

hi everyone,

i have a problem with the adobe acrobat reader. i use the microsoft surface book with a extendet screen (24 inch). when i open an pdf document on the 24 inch screen the resolution is normal. but when i open it on the surface book the menu and all icons are very small. other application automticly adjust the resolution (e.g. firefox, explorer, etc) but not the adobe acrobat reader. when i use the surface book alone the resolution is ok

have anybody a solution for that problem.