I purchased this plant a little over a month ago, and all of a sudden, these spots have begun to show up. The spots themselves are dry and can be popped out of the plant leaves where they've appeared (as a result, there is now a circular hole in one of my plant's leaves).
As the pictures indicate, the spots are roughly circular with black centers. Up until yesterday, the plant was kept in a mostly-shady, west-facing room and was watered ~1 time per week (when the soil was completely dry. Thinking the spots might be due to a lack of sun, I moved the plant over to a south-facing window (6+ hours of sun per day) yesterday.
Perhaps this is Cactus Anthracnose? If so, how do I treat it?
EDIT (More Information): As far as I can tell, the leaf edges are normal for this kind of plant (part of it's appeal imo). This plant lives indoors near a window, but not one that has been sprayed with anything recently. Additionally, none of the other plants in the vicinity have any issues. Two days ago, I wiped the leaves down with a mild soap/water mixture. I also treated one leaf with an alcohol/water mix, and another with a copper fungicide.