I had this problem as well. Probably it's the ink, not the Testors sealer, because I could produce perfectly clear multi-colored decals once. Some years later I had the problem you describe (using different ink at that time). It could be the decal paper too - it ages when left in the box.Thanks guys. Not sure why but the Testors decal sealer that I used seems to eat the printer ink. Not that I care for this little sideshow but worrying for future projects. Maybe because I used 2 coats.
BTW I always printed decals with the highest ink level possible (photo, highest quality, vivid, best - whatever it is called) - do not save on it.
The stenciling is really "funky" though - great job!
Cheers!