Sitting Meditation: not able to notice rise and fall of abdomen During sitting meditation, Most of the times, I am not able to notice rise and fall of abdomen

This problem is not getting better, even after doing sitting meditation for some time

Want to get advice on anything I can explore to solve this 

Metta
You can put your hand on your abdomen at first. After awhile you could probably spot the sensation without the hand. 

You could lay down on your back and put your hand on your stomach for a stronger view of the rise and fall.

You could make your anchor focus on the sensation of your bottom and legs making contact with the floor or cushion instead of the abdomen.

Hope this helps :) Metta