Hi gaureshk30144236,
Keep in mind that changing the allocation of experiences in an AB test will impact only NEW visitors to the test. So the reports may continue to show visitors in the 0% experience(s) if you have returning visitors that were previously assigned the now 0% experience(s). If I'm understanding you situation correctly, this could explain a 80:20 split after you switched allocation to 100:0.
To "push-a-winner" you might be better off deactivating the AB test. Then copy it, rename it, and remove all unneeded experiences. Finally, activate it. Now 100% of people will start seeing the "winning" experience. This also helps better preserve the "test period results" into their own separate activity for a historical view.
Hope that helps.
-Ryan