There is a ton of variables and while the problem may be related to where you see a string break, it might also be something completely different.

Have you tried different string brands? One thing that might matter is how you string the guitars. Are you creating twists or kinks and how evenly you stretch the string. Might be worth watching some videos about it. We all forget things even if we've learned them once and there are worse and better methods.

Just two breaks is still mostly just coincidence. Especially on two different guitars. And strings break. Especially top e.