It's just that these people weren't very confident in confirming it; plus, his identity spread, and those big figures didn't dare to openly provoke him because they had to show respect to the Medicine Saint.
Various reasons led to him safely getting through this difficulty.
Lin Yifan didn't know if the Medicine Saint was aware of Qingxu Immortal possessing the Blue Immortal Ring and the matter with the void creatures. If he knew, then Lin Yifan would be in trouble.
Because if that's the case, the Medicine Saint would know he possesses two Immortal Rings, which would be extremely unfavorable for him.
If the Medicine Saint decides not to wait, or doesn't want to use him anymore and then decides to take his Immortal Rings by force, or even kill him to prevent future troubles.
All of this is his own speculation; hopefully, the Medicine Saint doesn't know.
