That doesn’t look like crazing to me. It might be flashback, but that’s not consistent with flashback symptoms exactly either. You can see evidence of flashback alone the edges (the regularly spaced “pits” in the edges are consistent with flashback), but the damage to the mirror on the rear looks different, almost like a defect in the acrylic. Have you peeled the masking off on a small portion to verify that the acrylic looks ok to start?
Crazing looks more like hazy areas that are filled with small cracks. Did you try to clean the acrylic after you cut it? Crazing can be caused by using the incorrect cleaning regimen.
There was a thread recently about avoiding flashback in acrylic by raising your material off the bed, I don’t have it handy, I’ll go look.
EDIT: Here it is- Suspended ablation