Font size in Windows 10 on new Lenovo Yoga Laptop

When I use Biblioscape 10 with my Yoga laptop (with Windows 10) displaying on an attached external monitor (either at work or at home), Biblioscape works fine. But when I do not have an external monitor, turn on the laptop, open Biblioscape thus viewing Biblioscape on the laptop's own monitor, the default fonts are abnormally tiny and difficult to read. When I try to use the Options Change Default Font command in Bibliosapte to try to change the font, the font is not changed. All other aspects of Biblioscape appear to function normally. I don't see this happening with any other programs.
But interestingly, if I have Biblioscape running with an external monitor and just separate the monitor from the laptop without turning off the laptop, Biblioscape then shows with the fonts at the appropriate and readable size. Likewise, with the external monitor viewing the Options Change Default Command works.
Is this a Widows 10 issue, and issue with the Lenovo Yoga Laptop, or an issue with Biblioscape 10?