Your monitor is frame-converting the weird refresh rate you’re feeding it. Short of buying another monitor (and good luck finding one that will display that without conversion!), unfortunately there’s no solution.
Would a FrameMeister work? I’ve got one relegated to just capture at this point in my setup, but I could reroute it.
Since you have one on hand, you might as well give it a shot to see if the result is acceptable to you. That said, the Framemeister, like your display, will be upsampling the 57somethingHz refresh rate to 60Hz, which will again introduce jerkiness, the difference being that the resampling is done by the Framemeister rather than your display.
On that note, I wonder if a Freesync-compatible monitor would be better able to handle wonky refresh rates like this.