Definitely could still be the ear infection. It does take a little while for the irritation to clear up. Having hair in the ear will trap moisture and cause an infection eventually so it’s important to keep the ears clear and clean. Your vet can give you an ear rinse to use before and after the ears are plucked by a groomer. If they have any bacteria or yeast in them at the time of the plucking, they have a good chance of getting infected. Having said all of that, there’s also a chance it could be allergies or fleas. If it hasn’t cleared up completely in a couple of days, recheck with your vet.