Export pdf some pages will have black cover

[a9wei]

Sketch version 50.2

After export pdf, some pages will have the black cover that didn't exist on the artboard.
Please refer to below:

[DWilliames]

Thanks for this @a9wei.
This plugin is built upon Sketch's own PDF exporter — so are you able to check for me if exporting that Artboard manually via Sketch's export option produces the same results?

Also, does that artboard have a background colour set for exporting?

[a9wei]

Hi DWilliames,
No, exporting via Sketch's export option display normal.
The artboard background color is white, even I take off the background color it still produces the same results.

And just found not only shape's color but also font color and icon's color will be changed too.