Speed Maxing Out Too Soon

I have an Ortur LM3 that has a maximum speed of 20,000mm/minute. I confirmed this by typing $$ in the LB command screen and looking at the X & Y (and Z) values for maximum rate. I had a project to etch a photo on wood and saw someone else use 10,000mm/minute so I entered this and tweaked the laser power to get a good result. But, I know the laser wasn’t moving at 10,000. After my job finished I entered different speeds and looked at the LB time estimates and sure enough they go down until I hit 5,000mm/min and then they don’t change. Is there another place in the software that could be limiting the speed. - Thanks