not sure about ansible but white whale doesn’t really care about the pulse width, the only thing it affects is the clock output which follows the external clock exactly.
i just tried syncing both ansible and white whale (running orca) to tanzbar and no issues, it seems stable. looking at the sync signal on oscilloscope it’s at around 3V which might be a bit on a low side, i do have issues with missed triggers when i sync from machinedrum and don’t have the GND IMP machine level all the way up (at the max level it’s around 5V).
what if you try to amplify it via some other module?