The mind map disappeared when tap on scroll bar

Hi there,

I made a note on mind map, and it disappeared when I try to use scroll bar.
I have capture the video for your reference. Is it a bug or something I mis-used?

The video is attached here,
https://drive.google.com/file/d/1gr7TQUVVU5P8Ldzk2aMxuIATAuN-yYP0/view?usp=sharing

Thanks & Regards