I fish these lines all the time. It’s hard to tell from your photos just how much they are sinking. Rapids, water undertow, or mixed currents can affect the line and pull it under - especially the front of the line which has a more fine taper.
Your photos make it look like some sections are floating and some are sinking throughout a short length of the line. This does not seem normal. However, considering my long history of using quality Airflo products, it’s hard to believe their replacement line would be damaged, too.
I would call Airflo to discuss. Try a different piece of water, too, if you haven’t already. Good luck!