The Sainsmart PROVerXL 4030 operates in negative coordinate space and lightburn expects it to operate in positive coordinate space. Without the correct grbl configuration lightburn will send the axes to the wrong locations.
The correct grbl configuration commands can be stored in lightburn macros.
The first macro sets the grbl configuration for laser operation.
The second macro set the machine back to cnc router operation.
G10 L2 P1 X-397 Y-297
G10 L2 P1 X0 Y0
You can get the exact values for X and Y above by homing the machine and reading the machine coordinates from your software (candle, ugs, openbuilds etc.)