I've contacted Murat a while ago explaining the situation and asking for a new top cap and he said that the top caps are made for every specific razor individually and there's no way of getting a replacement, since it will probably cause even more issues. I really don't know what to do, but needless to say I'm very dissapointed.
That's not good, if he said that.
I would explore sending the entire razor back to him so he can examine it and suggest some
solution. His English is poor and he uses google translate so a lot can be lost in translation as well.
Hope you get it sorted because his razor the Sailor MC 2021 works really well for me.