The image background generated by makeimage method is incomplete

GoJS
1

The background is incomplete when zooming to < = 80% using goole browser

code：
var img = self.diagram.makeImage({
background: ‘#ede0dd’,
scale: 1,
});

{886156fe-537e-45ec-a3fa-853f86a4585c}
{886156fe-537e-45ec-a3fa-853f86a4585c}1699×323 50 KB

2

Don’t want the background to be transparent

3

Version: 2.1.21