I seem to have the same issue. The star base screen has the background in front of the buttons. They are still there and can be functioned but good luck on finding the correct one. FYI I play on a Surface Pro. If the game gets sluggish I just play in strategic view. Showing my age here but I grew up playing games with chits and hex maps (Squad Leader, Star Fleet Battles, etc...) so the strategic view is where I spend most of my time anyway. This is a great game!
Edit: I turned on all of the graphics options as I have been playing low res (Surface Pro) and low and behold... Star Base build options; yea! I had suspected a graphics issue so I did the opposite of what I had been doing. My tablet is slower in game but working again. With the shared memory for graphics suspect that late game will be painful using my tablet.