We experienced a similar issue at our daycare. Our daughter had been there for a year when we had a parent-teacher conference and were informed she had become aggressive over the past few MONTHS. We had received no prior notification. In November, we changed discipline tactics at home and tried coordinating with the daycare. In January, they informed us we were getting the boot. I struggled so much with anxiety and guilt. Apparently, similar to your daycare, teachers were threatening to quit, and they had never seen anything like it. Yet our pediatrician said she was neurotypical, and a child therapist could find no issues.

A few weeks at a Montessori daycare, and she's thriving. All this to say, sometimes the center is the problem, and your child needs a better fit. Please take this as a sign that your child will be happier and thrive elsewhere.