Question For Shooting Instructors and Glocks

As the title says...why do I have to modify both my Gen4 G19 and Gen4 G26 to eliminate casings to the face by either polishing the extractors/or using a LWD extractor, modifying the ejectors or using a lighter spring on the rsa?

BUT...both my Gen2 and Gen4 G23s have never had an issue with casings to the face or failures of any kind and I haven't had to modify either pistol.

Seriously, what am I doing wrong with my 9mm Glocks that I'm not doing wrong with my .40 S&W Glocks? If my grip is bad, why wouldn't it effect both my 23s instead of just my 19/26 pistols?

I've been shooting Glock pistols (a G21 and switched to a G23) since 1999 and NEVER had issues with failures or casings to the face, but when I decided to get into shooting 9mm this year I'm having to modify both 9mm pistols to eliminate casings to the face...is it just bad luck with my Gen4 9mm pistols?

BTW, I'm NOT whining...I seroiusly can't figure out why I have NO issues of any kind with my 23s, but have issues requiring modifications to both my 9mm Glocks.