Recently I ran out of my Cobalt Arrows and didn't refill before I ran out. My damage was around 220 per light shot, and after running out of arrows it went to 160 dmg, so I refilled my arrows using the "refill" and my dmg continued to be 160 dmg. I stopped, checked my gear it was cobalt arrows, and after closing menu and going back, it went back to 220 dmg.

I did kill more than just the 1 mob before looking at my gear tab.

The issue is, once you run out of all 999 arrows, it defaults to the weathered arrow dmg, and unless you go into gear, the dmg of the better arrows are not reflected.