Why are a few of my characters getting fishing fatigue within 10 fish?

So I have these characters (I don't remember the name of them all, as I have 8 characters), 2 or 3 of which cannot fish more than 10 fish. I've had problems in this same respect on a different account I had a few years back. But I don't understand why this is happening. For each of these characters, they are fishing with a job post level 20, and I'm pretty damn sure I've had them at least 2 weeks, more like 3 or a month. WHY IS THE GAME ONLY LETTING ME FISH 5-10 FISH?!?!?!?!?!?!?!!

What level fishing do you have? Also talking to NPC for fishing skill and finding out if you need to level up skill cap (same as skill caps every 10lvls for regular crafting).
Also check into getting a set of Fishing Tunica gear too. Pelican / Albatross rings might help