Some shapes don't exist on the thumbnail

Aspose.Slides Product Family
1

Some shapes don’t exist on the thumbnail. Slides version 2.8.9.0
Sample attached.

2

All braces condensed to a line have TextFrame with empty text and
FitShapeToText property set to true. That is correct rendering.

3

But it is rendered fine in PowerPoint… May be there should be any exclusion for FitShapeToText property at shapes with empty text?