I have observed the issue shared by you and request you to please provide the Java details as well as Operating System details on your end. Please also first try using latest Aspose.Slides for Java 18.11 on your end as well before sharing the information with us.
I have worked with the presentation shared by you using Aspose.Slides for Java 18.11.0 and have been able to observe the issue. A ticket with ID SLIDESJAVA-37421 has been added in our issue tracking system to resolve the issue. This thread has been associated with the ticket so that we share notification with you once issue will be fixed.