Two same windows opened when startup

Recently, I begin to use MarginNote 3, it’s a great app, I used it to take video note while I had been playing MOOC video.

But even I just take note in one video file. Every time as soon as I open MarginNote 3 there are two same windows existed just like attachment shows.
One of these two windows is blank. but has the same layout as the other.

So I have to close one manually every time.
It’s not a fatal problem. but a little annoying.

Is it a bug, or some function. How could I get rid of this situation?

Hello

hello ,Do you try to save the content and restart it?

Kind Regards,
MarginNote-Echo
Support Team