Omtech Preenex Laser Machine Tube Inconsistent and weak in cutting plywood.

Tube is not the Yongli H6 they advertise as. Machine came with a tube that's marked with a non-sense manufacturing date on the label.

After running the laser for a few minutes, cutting power gets weak.

Material: plywood 5.25mm
Speed: 10mm/s
Power: Initial setting - min 30% max 35%; raised to 90-95% max.

Autofocus sets the ideal cutting distance. Autofocus seems to work fine. Also manually checked the gap.

Also the laser dot does not turn on. It was working until it was touched once to make an adjustment to its holder. Never coming back on after that.

Also the power does not go off with the switch once it is powered on with the key switch. Machine has be to unplugged to shut down.