This is completely normal. Analog sources have always had a pixel or three of black around some or all of the edges. 3/4in tape is even worse. When you bring in Beta footage and play back to your monitor u will not even see it. Shrink a video clip back into a small box and you will. I have always cropped the black when less than full screen. Don’t even worry about it. I have seen this with Media 100, insync razor/DPS, black magic, aja, it’s normal trust me.