Touch ID not working after updating to 13.4.1

Yesterday I updated my iPhone 6s to newest ver. 13.4.1. Immediately after rebooting the error message “Unable to activate Touch ID on this phone” popped up. So, I try resetting all settings and rebooting a couple times but the problem persist. I don’t want to try factory reset because I believe it won’t help. How do I go back to my previous version of iOS?