dophidb GUI shows wrong file name on tab page

[l1t1]

I first open a.txt then open a2.txt, notice the original a.txt became a2.txt then open a3.txt, notice the origanl a1.txt and a2.txt became a2.txt and a3.txt after clicked on each tab, their names returned the original

btw, there isn't a new file feature, so I have to save a file outside the GUI, then can I open it.