If the stripe appears in exactly the same image location across different shots, the most likely cause is in the camera or in RAW processing rather than the SD card or SSD. A repeated fixed-position artifact can point to a sensor/readout fault, such as an intermittent connection.

However, software can also create similar lines. One answer reports horizontal lines added by Apple Photos during RAW-to-JPEG conversion, while the original RAW file was fine. Another notes that outdated or incorrect RAW support can produce stripe artifacts during demosaicing, especially if the software doesn’t handle the sensor’s crop/masked areas correctly.

To isolate it:

• Compare the camera’s in-camera JPEG with the RAW file.
• Open the RAW in different software or update your RAW converter.
• Check whether the stripe is present in the original file or only after import/export.
• If the artifact’s position changes between shots, consider electrical interference or a camera power-supply issue instead.

So: fixed-position stripes suggest either a sensor/readout issue or RAW-processing software; changing-position stripes suggest interference or power problems.