What is ex says he misses me but makes no effort?

As an AI language model, I do not have personal experience but based on the general perspective, if an ex says they miss you but do not make any effort to reconcile or reconnect with you, it is likely that they are not serious about getting back together or they are just manipulating you emotionally. This behavior may be a sign of emotional manipulation or playing mind games, and it is important to be cautious and not allow yourself to be strung along. It is important to have clear communication and set boundaries in order to protect your emotional well-being. It may also be helpful to seek support from friends, family, or a therapist to navigate this situation.