17 September 2021
Thank you for reporting the issue. The problem seems to be in the fact that you don't have an XSD. When you use the "Infer schema from sample XML" functionality, Docentric Add-In for MS Word tries to infer the schema from that XML. In XML everything is string and the Add-In tries to be "clever" and "infers" the data type from the XML string value. For example, when a string value consists only of digits, it will guess the type is integer or perhaps double if the decimal delimiter is present. In your case, its guess is wrong.
There is one solution to this problem: you need to generate the XML schema (XSD) and use it in the Add-In. You can use Visual Studio for that. Visual Studio will most probably make the same mistake, so you will need to manually fix the mistakes.
There is also a workaround: Instead of generating an XSD, you can traverse through the generated sample XML and manually change the string values so that they don't represents numbers anymore.
Let me know if this helps.