After an initial test, I am able to reproduce the issue as you mentioned by converting your template file to PDF and XPS formats. The blank Row 3 in the PDF and XPS formats with a color fill cell pattern shows the grid lines which it should not show. I have logged a ticket with an id "CELLSNET-41981" for your issue. We will look into your issue to figure it out soon.
Please download and try our latest version/fix: Aspose.Cells for .NET v7.5.3.4 your issue is partially fixed in it. PDF rendering is OK but XPS rendering still shows the gridlines. We are still working over it, once it is fixed, we will let you know here.
Good to know it solves the issue regarding PDF rendering. Regading XPS rendering issue, I am not in the position to provide an eta at the moment, if I have an update on it, I will let you know immediately here. Please keep in touch.
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Feel free to contact us any time if you need further help or have some other queries or issue, we will be glad to help you soon.