iPad texting issues

My daughters iPad does not have cellular capabilities but we have always been able to send and receive texts on it by using her Apple ID has the contact information and over Wi-Fi networks. Now suddenly only certain android numbers won’t work anymore. If she tries to send to a new android phone number that she has not sent to before she gets a red “not delivered !” warning. I updated the software, hard restarted and checked all the settings I can think of. Any ideas?