Xporter: Javascript regular expressions are not working

The issue is reproducible in Prod Jira Cloud

Step to Reproduce:

1. Access a valid Jira Prod Cloud instance with the Xporter  installed and enabled.
2. Download and add the provided Xporter template file: (Settings > Apps > Xporter > Templates). XPCTP-1328 (1).docx
3. Create a test issue and in the issue's "Description" field, enter the following text : Text: abcdefg, Issue key: DEMO-12345
4. From the issue, select Actions > Xporter, choose the previously uploaded template, and run the export.
5. Verify the file

Actual result:

All fields in the generated document are empty.

Expected Result:
The resulting file correctly shows the issue's key, the searched text in the Text within Description, Key within Description fields, and some text with at least one occurrence of "This is a test" in the Replace within Description field.