Bootstrap Blocks in 3.1 fail to work as expected

Launch Pinegrow 3.1.

select New file / Bootstrap blocks.

Drag header to page, and a couple of content blocks to fill page.


No possibility to scroll down design panel.
Blocks do not fit width of panel.
Browser preview also fails to offer scroll.
Browser preview width does not fill browser regardless of width.

Used to work fine but not in new version.