My guess is that the DPI is funky on that device. I just did an analysis of a Lenovo Yoga 10" tablet (similar resolution, probably same problem). There are some suggestions on DPI fixing stuff there. You should be able to run at 160 (MEDIUM) and take advantage of your 1280x800. My guess is you are running at 213 (TV) or higher and your “virtual resolution” is much smaller than 1280x800.
https://community.roonlabs.com/t/lenovo-yoga-stuck-in-portrait/10749/39?u=danny