I just checked in for a flight starting on UA intl then with a local connection on LH. I was able to email the BP to myself. I then went to my mobile app and noticed the BPs are not there. Usually they will show up upon refresh. I tried to reprint, but it only gives the email option.

I recall that on previous intl trips, it would show me the mobile BP. Is there something specific if there is a non-UA leg?

The email attachment did include a BP for the LH leg (UA codeshare). I had planned to checkin on the LH site as well but maybe that isnt necessary anymore.