Audrey Ficus help – what’s happening to the leaves??

What’s happening to my new(ish) Audrey ficus? Some leaves are eaten away, a couple have dried and dropped, and I’ve found some white stuff on some leaves (almost looks like bird poop, but it’s not clealry!). Is it mealybugs? powdery mildew? something else? Tree is over 5ft tall and only got it a month ago or so. We just put a grow light on it, since it doesn’t get the best light…and I historically don’t have the best luck with larger plants. But we’re really invested in keeping this beauty alive and thriving! So how do I do that?? Thank you!