If you are experiencing this issue, please right-click on your Citrix Receiver icon:
If you are having trouble locating this icon, it can be at the bottom of your windows screen within the ^ icon of your toolbar.
Select Advanced Preferences and then select the High DPI option from the list:
In the Scale the session for the high-resolution screen, please try the 'No, use native resolution' or the 'yes' depending on your individual computer settings.