Issue with Retrieving Updated Base64 After Using insertFileFromBase64 in Word Add-In

[Piyush-IT]

We are developing a Word add-in, and one of the key features is the ability to:
-Retrieve the Word document as a Base64 string (including OOXML content such as custom XML parts) and replace the document content using the method below:

// Insert the modified Base64 OOXML back into the document
Retrving base64 code.txt
However, when we replace the content and save the document, retrieving the Base64 content again does not provide the updated or valid Base64 string.
await context.document.insertFileFromBase64(base64Content, "Replace", {
importTheme: true,
importStyles: true,
importParagraphSpacing: true,
importPageColor: true,
importChangeTrackingMode: true,
importCustomProperties: true,
importCustomXmlParts: true
});

Here are my questions:

1. Are there any limitations with the insertFileFromBase64 method when inserting content? If so, is there any documentation or reference for this?
2. After replacing the content using the above method and saving the document, why does the Base64 retrieved afterward not reflect the updated content?
   This issue is a blocker for us, and I would appreciate your suggestions on how to resolve it.