The fly looks like a Long-legged Fly, and they are actually beneficial insect predators that help provide control of pest insects (both as adults and as larvae). Several species occur in Maryland. If they routinely appear near your container plantings, that may be because they are hunting for prey they detect among the plants. Here's a bit more info:
http://bugoftheweek.squarespace.com/blog/2019/6/10/coffee-and-long-legged-flies-dolichopodidae

https://ohioline.osu.edu/factsheet/ent-69

Many organisms can cause holes in leaves, such as on the sweet potato vine in the photo. Often, beetles are the culprit, though slugs and snails and a few other kinds of insects may chew holes in leaves as well. If you check the leaf undersides or inspect the plants at night, you may find the pest responsible. Tortoise beetles in particular are fond of sweet potato vine.
https://extension.umd.edu/resource/leaf-feeding-beetles-flowers

Treatment for the hole-chewers probably isn't needed for plant health since significant damage is rarely done; plants should outgrow the damage and the undamaged parts of the leaves are still feeding the plant. For aesthetics, you can pluck off any chewing pests you find (beetles, slugs) and remove the worst of the chewed leaves, but chemical intervention should be minimal so beneficial insects and pollinators aren't harmed. If necessary, an organic pesticide with the active ingredient spinosad may provide some control while sparing non-pest insects around the plants.

Miri