Homing times out on long axis? (no replies)

Hello all,
I'm using Marlin to run a CNC router with a long axis. Throwing G28 commands on the long axis, the homing procedure starts and stops after roughly 6 seconds. I can keep running the command over and over and it will eventually hit the endstop and stop with no problems.

Is there a way to length the homing time out? I can't seem to find the settings in configuration.h r _adv.h

Thanks!