My Pycharm's debugger has been working fine. But today it suddenly got a problem. When I started the debugging in one file and traced the execution logic into another source file, the current source file doesn't show up, namely the UI view stays in the original file. This caused a big trouble, because the execution code doesn't sync with the actual file that is currently in the focus.
I restarted the PyCharm and tried again, but it doesn't work either.
What might cause this?