That is weird how it looks like it's being sent back and forth between Nanjing and Shanghai. I wonder if was supposed to leave from Nanjing, got misrouted to Shanghai, and is now corrected?

The difficult thing here is that "Departure export customs" is often the last tracking you'll see from China; the status will look stuck for several weeks while the item is in transit, and then the next update you'll see is when the destination country scans it on arrival. In the case of Canada Post, they've decided they don't care enough to post scans for inbound international registered items online any more, so you won't get any updates in Canada until the item shows up at your door.

Ok I opened dispute, but could it be just a glitch? I mean it has really been only 23 days, under the average 30 day from China to Canada.

1. If you are talking about this tracking it seems OK:
International Mail# EV933848672CN Tracking Result
Summary
Tracking number Origin Destination Status
EV933848672CN CHINA SPAIN On route

History Detail
Local date/time Activity Location Remarks
10-Sep-2016 21:15 Received by Post Office 200888
11-Sep-2016 23:03 Item returned from export Customs/Security SHANGHAI EMS
11-Sep-2016 23:08 Departure export customs SHANGHAI EMS

2. The item was sent to Export Customs/ security and pass the inspection. Then the item was returned back to them here:
11-Sep-2016 23:03 Item returned from export Customs/Security SHANGHAI EMS

3. Then the next tracking is saying that it's departing from:
11-Sep-2016 23:08 Departure export customs SHANGHAI EMS

That is 5 minutes later which make sense to me.

4. If China Post does not advise electronically Spain Post that a parcel with the tracking number EV933848672CN is coming to their country most definitely Spain Post does not have the number and can not start the tracking of it.

5. As soon as the parcel come to your country, Spain Post will start the tracking of the parcel unless China Post before that give them the info about the parcel coming their way.

Hope this help.