Anyone have insight into reciprocity when dating?

Hi everyone, I'm not sure if reciprocity is the correct term but basically I'm wondering how I can address this issue with the guy I'm seeing. He is physically responsive and often he likes to initiate physical contact with me, however I feel that he is emotionally distant. It feels almost wrong of me to say that about him because he has already introduced me to all his family and friends and wants me to visit his family with him again in the near future. He's even asked me about going on holiday with him soon. However he seems to have great difficulty with maintaining communication when we are not together. He doesn't like phone calls or video calls and he isn't reliable with texting either. It's almost like I'm not quite sure where I stand with him. It's like there are two different versions of him (the version that appears when we are together and the version that appears when we are apart). I have read on a few help sites that this can all be related to reciprocity and can be helped with an honest discussion. Does anyone have any advice or insight that could help?

Many thanks everyone x