I'm having the same issue, and also my first time running into this bug: no mods in my mod folder, tried reset object on both the Sim and the fishing sign multiple times, and tried repairing my game. No waving arm animations or anything from my Sim either, and the interaction disappeared in my case as well. He admittedly was Very Tense when I tried (he's a Vampire who had the Dayphobia weakness active at the time, and had a burnout so I tried to send him fishing to lower the burnout moodlet), so maybe I'm just stupid and it's his mood causing that.
But if this is a bug in my case, then it could possibly be caused by a pack conflict. I own most of the packs (the only ones I don't own are Home Chef Hustle, Journey to Batuu, Tiny Living, and most of the kits, but I do own Simstimates), so sorry, but I have no clue which packs exactly would be conflicting here. ☹️ I honestly don't even know in which exact pack this burnout feature that my Sim was suffering under is included: This fishing bug definitely hit me after downloading Horse Ranch and Growing Together, though. I haven't run into it before those two packs were installed.