Brake issues

Hey, all

Doing some work on a 2008 Sonata. Replaced the master cylinder and some split brake lines. Replaced one line, had the car stopping then another split.

Bled everything starting with the wheel furthest from the master cylinder and ending at the wheel closest. All of the air is out of the lines

Brakes are still very soft and not capable of stopping a car quickly.

Thoughts on where to start? Bad caliper(s)? Brake booster?

Thanks in advance