Deae Dr Osama,

Here is an answer I found from Research Gate website.

How do I add a department to ResearchGate?

From any page on ResearchGate, click the arrow next to your profile picture and select Your Profile from the drop down menu. From any page in your profile, you can edit your Photo, Degree, and Institution, Department, and Position by clicking on Edit (the pencil symbol) next to any of those items.

I think following this, the Research Gate algorithm will start showing your department work at home page again.

thanks, Dr Ibrahim, but I still cant see my department work as I used to do