Bezier handles are only available on certain properties. In the graph editor press the g key to bring up the pen tool and then hover over any of the keyframes and hold down the Alt/Option key. I the pointer does not change to the convert point tool then try selecting a different graph type. If you still don't get a convert point tool (sideways V) then you have chosen a property that is not compatible with bezier controls.
For more help, and better help, paste a PrintScreen screenshot of your entire AE window with modified properties the layers giving you problems selected and the composition selected in the Project Panel so we can see what's going on. If you are on a Mac then press Shift + Ctrl/Cmnd + 3 to take a full screenshot of the app and drag it from the desktop. If you are on Windows press PrintScreen and paste (Ctrl/Cmnd + v) so we can see what is going on.
If you right-click on the keyframe (back in the regular timeline) and choose ease in, and then go back to the graph editor, do you have a Bezier handle like you expect?
I'm having the same exact problem except I have two layers of the same type of image, both .ai assets. The first one I applied easy ease in and out and the used the graph editor to adjust the handles, no problem. Applied the exact same workflow to the second one and the handles are not available.
So to answer your question for ghazia, the first time applying easy ease did work, the second time it did not for the same type of object and the same type of value (position).
Any ideas? Thanks.
I solved it but not in an informative way for other users. I ended up copying the keyframes from the asset that did contain handles into the object that didn't and the handles appeared. Still not sure what makes them available and what doesn't.
For those with this problem, try to find something that does have handles, copy and paste, then you can adjust them to that object's needs.