I have attached an image that shows several parallel blue, green and red streaks after stretching in GIMP. I took two sets of pictures of NGC 2024 last night with different filters. Astronomik H alpha and Astronomik CLS. Same session, darks, flats and bias on both. The streaks only show in the H alpha set. The filter looks pretty clean. Used APT to capture. The thumbnails did not show the streaks, but hard to tell.
My setup is an 8 inch Orion Astrograph. ZWO294. Gain 200. 90 seconds. 45 images of each filter. I did not combine them as the H alpha filter image had these streaks. Used DSS on both. GIMP in post processing.
Could the H alpha filter be causing this?