Greetings from Syncfusion.
We suspect that the azure machine is running in US culture which may cause change in date format to US culture as ‘8/27/1990’. As per Microsoft Excel behaviour, the default date format is updated according to the machine culture. So, we request you to change the culture as Dutch using below code snippet before initializing ExcelEngine to resolve the issue.
System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo("nl-NL");
System.Threading.Thread.CurrentThread.CurrentUICulture = new CultureInfo("nl-NL");
ExcelEngine excelEngine = new ExcelEngine();
IApplication application = excelEngine.Excel;
Kindly try this and let us know if this resolves issue at your end.