I kept banging my head against the desk trying to figure out what i was doing wrong. Then I started to trace my steps back and undo everything. Wishing there was a right click Undo-Multiple, after about 30 clicks I got my drawing back to the step before performing the Boolean subtract, and the problem went away. So then I tested it again, performing the Boolean subtract and that confirmed the error. Example:
each circle is .3550 x .3550:
Now I will subtract the pink layer offset from the grouping of blue circles and that distorts all of the circles inconsistently (meaning they’re not all distorted uniformly). Some are .3540 x .3550, others might be .3537 x .3550, others .3534 x .3550 etc.
I have also tried (with the same results) locking and unlocking the aspect ratio on the individual circles as well as the grouping of circles. No luck.