I recently turned on the authentication on app opening option. I have found that on my device (beryllium running Pixel Experience ROM), that although the auth works fine, it does flash my balance, statement, etc. (i.e. the default screen for the app) before blacking it out. I would prefer, if possible, that the app didn’t allow any view of my balance before I’ve authed with my fingerprint.
I’m guessing that’s a rooted device
Not sure you’ll get what you want, it works perfectly fine on non rooted devices so will be something specific to the ROM you are using
mine does the same Samsung s9 & it’s not rooted