During the quest “Iskaaran Fishing Net” I went and collected the Kelp and Stones. Flew back to Tavio to make the Fishing Net. Tavio instead just had the quest completion on arrival instead of after making the net, so instead of making it just handed the quest in and tossed the respective Kelp and Stones.
From there, “Setting Your Very Own Net” quest seems to have been broken. I know the location and limitations from having the area Low, from my Alts that have had the quest work properly.
I also cannot upgrade the Fishing net, even though I have passed the required Reputation and Fishing.