Hi there! I'm happy you are enjoying the game!
Ok, so a few things is going on:

- Bite Speed: It's how fast a fish will bite. I mean the time while you are waiting for a fish to bite the fishing rod, and the (!) symbol shows up.
- Auto Fishing Speed: It's the actual time the character is "struggling" to catch the fish that have already bitten and are in the water.

Now, Auto Fishing time depends on the level of the fish. So, for example, a lv 1 fish takes like 15 seconds to catch automatically if you wait in idle. But a lv 2 fish takes around 30 seconds.

If you buy an AutoFishing speed that reduces 3 seconds to the auto fish time, now you'll have to wait 12 seconds for lv 1 fish, but 27 seconds for lv 2 fish.

I know it's kind of confusing, but the fish is stronger, so, it is more difficult to catch!! (Aaand the progression makes sense! haha)

Lastly, bite speed is a special stat. Actually, I don't think there is something in the demo to increase your bite speed time.

I hope that makes everything clear. But I agree that it is kind of confusing, and I apologize for that. I'll find better ways to describe those stats.