Hello ? I'd like to ask for advice or hear opinions. My daughter has b…

Hello ? I'd like to ask for advice or hear opinions. My daughter has become capricious and nervous. Although everything was fine before, she often hangs on her chest, she doesn't know what she wants. She understands, explains everything. She's noticed that she stopped repeating words when you tell her, for example, "Say 'come' and show me how a bear does it." She started ignoring, silent and all. She became one-word. And also, I noticed that she started grinding her teeth, the pediatrician said that this happens by itself and will pass. What could be the reason for her behavior?