Laser engraves darker on one side of bed than other

Hello folks. I'm scratching my head w/an issue of my Gold Mark (China) 6090 laser engraving darker on one side of the bed than the other. I have attached some pictures (engraved the words TEST in the corners of the board, much darker on left). I thought this would be an alignment issue but when I check alignment is appears to be good (see attach pic). The alignment burns are right on top of each other when the tape is placed on the engraving head mirror and test fired beside the #2 mirror and farthest away from the #2 mirror. Does the alignment look OK to anyone w/ experience? This is my first laser machine, hopefully I'm missing something. I've already aligned the bed of the machine also. It was out a bit on delivery. Thank you much!

Clean mirrors and perfect alignment are key to getting even power across the bed.

Press on the edge of the tape on the optic hole so you can see a circle from the hole and you will be able to better measure your alignment