Below picture is 5mm acrylic, engraving with 1000mm/s speed, 15% power.
Reason:
This behavior is not because of a fault. It is due to the fact that the actual output power is with certain fluctuations and is unstable.
Solutions:
1. Increase the power.
Connect your machine and computer successfully > Vendor Setting (password is RD8888)> Read > Laser > Laser freq(HZ)> Change to 15 > Write