tl;dr: Slow Down
As @jkwilborn identifies, the speed the head is traveling as it sweeps back and forth is a major factor in the calculation that would trigger this ‘Frame slop over’ message. Just like with driving a bike or car, the faster you go, the longer it takes to slow for a turn.
As you increase the layer job / processing speed, your Ruida control system adjusts the amount of further movement required to change direction. If you adjust the speed downward a little and check again, at some point you will find a speed for producing this layer without the Frame slop message. Often, it is the size or placement of the job within the laser. Yet, many more times this message is related to the speed you are asking the system to travel, and it simply can’t change direction in the room given. 