Late fees during Covid if tenant is not in distress

[Katy Fleming]

I have a tenant who has paid rent late a few times, and is now refusing to pay rent, stating the reason as a small repair that needs made (won't go into details, but I always keep on top of repairs).  I've forgiven their late fees in the past when I was contacted in advance so the tenant and I can work together.  Now I'm feeling like they're taking advantage of the situation, even when they don't need to.  It doesn't appear that the tenant's work has been impacted by Covid. Can I charge late fees?