As tele-con with you, below described is some reasons.
we didn't continually purchase NSSMC plate in 2-3 months ago because our inventory still have a lot of this type and also happen low sale circulation currently.
According to SCM440 plate volume, there have 250 Mt at stock and sell in domestic around 5-6 months.
For S50C plate, most steels are from Korea due to lower price than Japan and they're able to use or apply what they need.