I had flight from PHX to LAX, and LAX to LHR, which had me for 5 hours at LAX. There was a schedule change that resulted in a 50 minute connection.
This sounds very risky to me, and I want to change it but looks like the only palatable option is to come into LAX the night before. If it matters, I am a 1K and this is booked in Polaris.

Should I change my flight?