endnote keeping citing one reference again and again


i am using endnot X8, the issue is when i put the ereference it only cites one of the refernce and when i want to pt another refernce the end note put the previous reference again and it is not changed. I tried with another word document and it is again putting the first refernce i have cited and it repete that again anad again so by changing the refernce to cite it put the first one again.

please help me