Excessive speed or too high acceleration can be cause of this issue. I had similar problems with Sprinter but after I moved to Marlin and found speed that works well for my device prints are fine now. I also have accelerations set to 750, but machine I am using is my design so I can't guarantee it will work for you. Also decreasing speed is a good idea to, even if it won't help you will eliminate one of the possible reasons.
If you can't fix it in firmware try playing with the settings in your slicer but keep a note of what your changing, there's nothing worse than altering your settings, finding it doesn't work and you've forgotten the original settings.
True that, never try to fix what's working