Fried Fish Falling Apart and Gummy?

Hello everyone, I tried frying some fish recently and had some trouble with it. Here are the steps that I followed below.

1. ⁠I fried fish at home using Pacific-caught whiting from Walmart.
2. ⁠I used canola oil and Louisiana fish breading.
3. ⁠I fully thawed the fish before cooking.
4. ⁠I dipped the fish into an egg and hot sauce mixture.
5. ⁠I coated each piece in the breading, making sure both sides were fully covered, and patted it in so it would adhere.
6. ⁠I placed the breaded fish on a wire rack while the oil heated.
7. ⁠I heated canola oil in a cast-iron skillet and checked the temperature with a thermal pen. It wasn’t exact, but once it reached around 350°F, I started frying.
8. ⁠The first three pieces fried for about 4–5 minutes per side. I removed them, let them rest on the same wire rack, and they came out crispy, light, and airy with no issues.
9. ⁠The next five pieces were fried for the same 4–5 minutes per side, but when I tried to remove them from the oil, they fell apart. I was still able to retrieve the pieces and let them rest on the wire rack.
10. ⁠When I bit into the pieces that fell apart, they had good flavor, but instead of a crisp crunch, the coating was chewy, sticky, and gummy.

Why did this happen?