He didn’t get the same excitement from talking to you on the phone as he did on the online dating site.
This is an experience that is confusing to those who experience it but it is actually not that uncommon in online dating.
You may have been having some really good conversations with a guy on an online dating site for a while and he may have asked for your number with the intention of hanging out, only to have him stop talking to you after one or just a few conversations with you over the phone.
Some connections can happen relatively quickly in that some people can send the initial message and may meet up with the person of interest face to face within just a handful of exchanges.
It all really depends on what the both of you are looking for and how well you are both connecting.