Yes I’ve read that. My experience is so much the opposite that i question the expertise & the source. I’ve had 12 dachshunds. All of them sweethearts.
I’m sure you have and that is awesome. However, that is NOT typical of the breed.
You can not change the DNA or natural instinct of the breed.
I know a lady who breeds Dachshounds. They are yappy ankle biters. So, are our Chis.