Those stripes are more often seen with a failing memory card but it is not the sensor itself since the same sensor is used on lower ISO images. If it does that on all images at higher ISO, even in daylight and fast shutter speeds, it would indicate a problem with the video amplifier that on that sensor is part of the sensor, on the same silicon wafer but off to the side. A sensor has one sensitivity, its base ISO. Higher ISO is gained by amplifying the analog signal of each pixel. With each step increase in ISO the amplification factor increases. To minimize noise, the fewest number of amplification stages are used for the gain developed. Higher ISO require cascades analog low noise amplifiers. It might that that when switching in an addition amplifier at ISO 1600, there is a fault. Another possibility that is related is firmware that controls the switching could be at fault.
To test whether it is related to ISO or time of exposure, try shooting at high iso in normal day time conditions. Does it work OK or now. If not, it is likely hardware amplifier problem, but if it is OK at faster shutter speed, the controlling firmware could be at fault. In that case try doing a full factory reset. That can be done by pressing and holding both buttons that have green dots next to them, for about 5-10 seconds. If that does not do it, try removing the battery and let it sit for a day or two, and reset again. That is a different reset action, using the same two button method.
Do those tests and report back if it only happens at long exposures or if high iso in normal conditions