You have given your ex a means of communicating with you so I don't believe that you would be seen as being uncooperative. However, if he was simply texting you, then I would encourage you to consider unblocking him and limit your responses to any text messages that you receive. Then you will eliminate all concerns that you are not cooperating, and you may gain potential evidence, should you need it in the future. Just because he texts you, does not mean that you must reply.

As for contacting the Dr., given what you have provided from your order, and his request that you not contact his Dr. without his approval (which I hope was in writing), then I think that your best bet is to just sit back and wait. If your ex contacts you about seeing his children, then you should continue to reply (in writing) that he needs to coordinate the visits through his Dr. per your court order.