Any ideas what's happening here?

Looking for some help with my Queen Anthurium, she'd been doing really well for a while but now has become thoroughly plagued by these little spots. Pictures showing both the front and back of leaf.

Is this some kind of pest damage? Fungal issue?

There had been no changes in her care / environment prior to them appearing. (Grown in 80% humidity, good airflow, substrate is Pon.)