When their heart is shut, they are unaware of the connection in a big way. When they feel their heart opening up and they feel the strong bonding process occurring, it is scary be around their other half, so they may run, in some way. They run in order to put their heart under control again. They want to close it up and block it from feeling.
It is important that they be shown compassion and patience. When they are experiencing this, opening up to their twin, can make them feel uncomfortable. Try and find other ways for them to open their hearts, even if it is not directly towards you. just get their heart open.
What are they passionate about? What do they love? If they are open to sharing that with you, then this is a good place to start. You don’t have to push them to see you and love you, you just have to help them open up to Love, in any way. When their heart is open, it will guide them in the right direction. You don’t need to control it. Trust that their heart will lead them to where they need to be. If their heart doesn’t lead to you, then trust that it is not time. No one had to tell you or convince you who you love. You discovered it all on your own. You simply had to have an open heart that was willing to love. The same goes for your divine half.
Just work on getting their heart open.