i think it has to do with the space he's in since its a closed area where only the successor can enter even if sol is one of his body. from what I'm understanding
Pfff so tearsome hehe even his companion couldn't Come out
He hasn't heard Solderate since he regressed so I think in order to send Jin back and break the curse on him Solderate is either really weak at the moment or possibly being punished. I don't actually know, just what I've always assumed since Jin used to chat to him before he regressed.
That was also my tough..also because she mentioned to Jin why he couldn't replay to him ... It was definitely crucial for them if he had contact with him yes or no? So maybe in the near future chapters we would see him again
So why can't he hear solderates voice???? That's why I'm curious