I'm having a similar issue with 09 flhp. ABS light came on and stayed on a few weeks ago, with no issue other than ABS would not function so long as the light was lit. Light went from erratically lit to now always lit. Few weeks later, front brake lever now hard to pull, usually frees up after a few good squeezes but remains slow and feels like pushing thicker fluid.
Thinking maybe water in the fluid or just old and contaminated, 70k miles on the bike. Gonna bleed it out and run all fresh DOT 4 this week, don't know if ABS light will go back to normal or stay on. Throws no codes. Rear brake is fine.