So there is no train from Zhuhai Gongbei, all the trains to Guangzhou are from the north station?

Yes, you are right. Train schdule for the journey can be searched at the following website:
https://www.travelchinaguide.com/china-trains/

There is a train to Guangzhou South Railway Station from Zhuhai Gongbei (border to Macau). This train started to operate on the 31 December 2012.

I hope this information is confirmed. I cant find anywhere the schedule for trains from Gongbei to GZ.

Yes, it is confirmed. I found this information in the Internet. The journey from Gongbei Railway Station to Gunagzhou South Railway Station takes 80 minutes. Ticket prices: first class 90Y, second class 70Y. I don't know the schedule, but most probably every 30-40 min.

ok the train station exist and I bought the ticket, so I can confirm this in 100%. the duration is 87 minutes, every 30 minutes are the trains to GZ. 70Y.