Issues with Report Name Conversion When Uploading Reports Using PostImportFile REST API

This is expected behavior (unfortunately) and comes from Power BI Service sanitizing the import “name”.

1) Double quotes
The import name is treated like a filename/title and Power BI strips/normalizes invalid characters. A plain " can cause the service to fail the “rename” step internally, and it falls back to a default name (what you’re seeing as “No File Model”).
Fix: don’t send quotes. Replace with safe characters, e.g.:

• Sales Report

• Sales Report - "Q4" → Sales Report - Q4 or Sales Report - Q4 (quoted)

2) Date-like names (23/12/2025)
/ is also not a safe character for names (it’s a path separator), so the service normalizes it. In some cases it also tries to interpret date-like strings and ends up shortening/transforming the title (your 2025 result).
Fix: use a safe date format in the name, e.g.:

• 2025-12-23

• 20251223

• 23-Dec-2025

Recommended approach
Always generate a “safe” import name before calling the API:

• allow letters, numbers, spaces, - _ ( )

• remove: " / \ : * ? < > |

• use ISO date format YYYY-MM-DD