Yes — these artifacts are consistent with a shutter problem. A bright band plus a partially darkened area in repeated frames strongly suggests the shutter curtains/blades are not traveling evenly, or are briefly sticking during the exposure. One community answer noted that if the band width changes with shutter speed, that’s another sign of shutter malfunction rather than a sensor issue. The follow-up inspection with the mirror up confirmed visible shutter damage/misalignment, making the shutter the likely cause. In short: this is not normal burst behavior, and the camera should be inspected and repaired by service if you want to keep using it reliably.