I was able to get both UA and LH on a call. The issue is LH now controls the ticket, and they don't have a way to update the flight numbers that UA should have done that before handing it over.
They tried re-issuing the ticket twice, and nothing changed.
They said the only way this can get fixed is at the airport, where they have manual control. But I'll loose out on attempting plus points, as it will be less than 24h.
Ugh....