Graphics card driver problem
It looks OK when you unpack it. It gets complicated when you start installing an OS on it.
Nothing to do in Windows 10 (several versions tried) as in Ubuntu the screen flickers.
Impossible to find the right graphics card driver: manufacturer's website, Intel ... None of them correct this flickering problem.
Moreover, Gigabyte has stopped updates since version 1.0,
I have the same problem with the Gigabyte Brix BMCE-4500C bought at the same time.