It's a phony BSD license, with an attempt to pass it off as the real thing with some verbiage. It's neither within the letter nor the spirit of the real BSD license.
I don't really care about that as a user. Maybe for FOSS purists it's important but copyright is a thing I as techy care nothing about. I can it for free and i can see all the source code. I'm not going to build a fork so the rest doesn't matter.
https://docs.openwebui.com/license/