Thank you for contacting Syncfusion support.
We have tried to reproduce the issue, but it works properly at our end. We have shared a sample as per your requirement which can be downloaded from the following link.
Kindly modify the above sample to reproduce the issue and share us along with issue reproducing input files. It will be helpful for us to analyze further on this and provide you the solution at earliest.
Note: The documents shared will not be disclosed and is only for the purpose to reproduce the issue. We assure you that the document will be deleted from our side once the issue is resolved.