Loginwindow tried to hijack service?

This is normal and something that Apple clears up most of the time and is almost always harmless when it’s Apple code dropping two versions of the library.

See this other example - How to fix the error: "AppleSpell" tried to hijack endpoint "it (Apple)_OpenStep" from owner?

XPC is an inter-process call where one part of a program calls out to another to do something, so these frameworks have a default location - see the actual warning that the same “name” is defined in two places, so Apple would patch that up going forward when you apply updates.

I’d focus on anything actually not working and then we can dig into it - you could get breakage if older code calls a newer version, so perhaps Apple shipped this during a transition period from older usage to a newer implementation.