Most of the time it's your drag. Back off of it and let them run with it.

I agree with previous posts. I'll bet the bigger ones are throwing the hook because they are ripping bigger holes in their lips. Composite rod + mono line = more shock absorbancy for both the hookset and the fight.

I'm a little different from most, but I fish a crank with a 7' top water rod. I also play the fish just like it is on a Pop-R type bait. I also let 2.5-3 lb. fish peel some drag. Good luck with your "fix" and hope that they stay buttoned up for you in the future.

Only thing you need is the right rod:

7' Medium

It will make all the difference.

I agree with these other guys. The problem is your rod. When I switched to a 7'10" crank bait rod I stopped loosing crank bait fish.

Loosen the drag

I used to have the same problem and I would give the opposite advice. Try throwing straight braid or braid with a clear leader if you're concerned the fish are line shy.

That is what worked for me. It was just too much play when I would sail that trap or square bill out too far.

Best of luck.

This could be a rod problem, however there are several variables you might wan to address. Rod choices vary between pros. KVD likes a glass style rod because he says the fish gets the bait before the rod reacts, but Rick Clunn says he likes a graphite Medium Heavy because he doesn't like to give the fish time to spit or adjust the bait before he sets the hook. Watch Big Mouth Forever and you will see how fast a fish can inhale a bait and spit it without you ever feeling it.
1. color- if they are not eating the bait well and you are hooking in the soft outside area of the mouth, then big ones pull off much easier.
2. speed- it could be that you are moving the bait to slowly and the fish are not reacting to it and are simply nipping it. Bigger fish are more leery than small fish and may only nip a bait before committing to it if they have a long time to study it. If you reel too fast they may not commit either. it can be a tricky thing to figure out what makes them inhale a bait VS nipping it.
3. hooks- just because you change hooks doesn't mean that you have chosen the right hook. A wide gap hook sometimes works better than a standard and vice versa. John Crews did a video about when he uses what style hooks. look it up on YOUTUBE.
4. Contacting Cover- If you are getting bit swimming a bait near cover the bite is not usually as aggressive as if you bounce the bait off the cover. Aggressive fish may leave the cover to trail or hit a bait, however if you bounce it off the cover they usually eat it much better without hesitation.
5. Line- although line size can be a factor, its not always a reason fish don't eat a bait. Many pros will tell you that they crank with 10-15#, but if they fish a square bill around thick cover they will go to 17-20# when fish react they rarely take time to look at the line before eating the bait.
Hope this gives you a few things to try. When you dial it in you will notice the difference. Many pros will tell you that they experiment with dozens of color, hook, and retrieval speeds before they dial in what works best for a day or even just a few hours.

If it has to do with cranking im going to listen to KVD

You've been fishing for over 50 years.. like myself. Your getting slower and starting to forget what you've learned. Any changes in what you've used for years will take some time to get confidence in.