Today I got this Three Soma (Generic brand) 9" monochrome monitor that I bought used at a local computer store, the monitor does work and also shows image as intended but looks like letterboxed and I tried adjusting the vertical size as far it goes but the problem still remains, could be a problem with the monitor or is normal?? (Theres no vertical hold on the back u.u )

(Sorry if you guys need to rotate your heads 90°, the images were taken by my tablet)