what does it mean?? Beijing Municipality, retained by the Import and Exchange Bureau does anyone knows?

Hi,
I bought some spares from China through ebay and the spares had to be returned to the seller.
Tracking the package now, I see the following message "Guangzhou City 51040034, retained by the import and exchange bureau". what does that mean. Also, will the seller be contacted or how does the process works in China when returning items purchased from China.

2025-11-16 11:23
Guangzhou 51040033, delivered to the carrier
2025-11-14 13:16
Guangzhou 51040034, the email has left [Guangzhou International Exchange Bureau] and is being sent to the next stop.
2025-11-14 12:48
Guangzhou 51040034, the mail arrived at [Guangzhou International Exchange Bureau]
2025-11-11 20:42
Beijing 10130047, the mail has left [Beijing Airmail International Exchange Station] and is being sent to the next station.
2025-11-11 20:42
Beijing 10130047, the mail arrived at [Beijing Airmail International Exchange Station]
2025-11-11 18:00
Beijing 10010200, the email has left [Beijing International Exchange Bureau] and is being sent to the next stop.
2025-11-11 13:07
Beijing 10010200, Export Customs/Release
2025-11-09 08:29
Beijing 10010200, retained by the Import and Exchange Bureau
2025-11-02 16:25
Leaving the Overseas Export and Exchange Bureau (not yet arriving at China Post)
2025-11-01 23:30
Send to overseas customs department
2025-11-01 23:25
Arrive at the Overseas Export and Exchange Bureau
2025-10-28 14:19
Send to overseas customs department
2025-10-28 14:14
Arrive at the Overseas Export and Exchange Bureau
2025-10-24 18:10
【IN】Received

Can you tell what does delivered to carrier mean it has been showing this status for more than a month now.