advice on if miss UA award flight on US air due to immigration
I have tried to search similar subjects but not very successful. My case is that in January this year I booked business class award travel using UA miles from TPE to AUS on Dec 19. The operating carrier are TPE->LAX (EVA) LAX-> PHX(US) PHX ->AUS(US). My question is if I miss connection flight at LAX due to either immigration or EVA delay, which airline will rebook me automatically or which airline I should talk to have my new connection flight? Things seems a bit tricky as US left star Alliance after March and merge with AA now. I'm both UA 1K and AA EXP now if help.
many thanks
CK8870