A question, is the IP address the same for different users? I mean if i create a new user on the hosting site will the ip address be the same?
Maybe yes, maybe no. It depends on how many different servers the company has available to hosting and if you get assigned the same one fo ryour data. If they have "HOST-SRV1, HOST-SRV2, HOST-SRV3", you could get placed on either one of those and they would all carry different IP addresses.
But if you got placed on the same one, then yes you would have the same IP address.
Also Domain name entries and IP addresses are not always a 1-to-1 ratio due to if he was connecting to "probe.filezilla-project.org" like you were, it doesn't
necessarily mean his data lives on the same server as yours
Out of curiosity, what was the correct IP address was that he was using?