Thanks for your reply.
I just changed some settings in settings>files, and the phenomenon seemed disappear. I think I might have a clue how the “bug” I reported happened, but I need some time to check and experiment carefully. I will record a video or add some details maybe at tomorrow. (I think I can reproduce such “bug” again.)
By the way, do you know where can find the further explanation on the behavior of
Obsidian to try to fix/resolve broken links? What is the algorithm or determine logic?