How can same video appear in most popular video list of 2 different regions?

I am trying to find 10 most popular you tube videos in 2 regions. But to my surprise

Issue 1.one of the videos is present in both region's most popular video list.

Issue 2:-And, this video does not match with the single most popular video retrieved for region 1.

Please see the steps I followed

Steps followed for issue1:-

I tried for regions r1 and r2 using following params

request 1(region:r1):-

      part: 'snippet,statistics',      chart: 'mostPopular',      kind: 'youtube#videoListResponse',      regionCode: r1,      maxResults: 10,

request 2(region:r2):-

      part: 'snippet,statistics',      chart: 'mostPopular',      kind: 'youtube#videoListResponse',      regionCode: r2,      maxResults: 10,

service url used is https://www.googleapis.com/youtube/v3/videos.

I am getting video_id "GXy1JwJ6vJ0" in both the lists.

How is that possible?

Steps followed for issue 2:-Now underlying problem is that this id "GXy1JwJ6vJ0" has as of now 6.1 m views and present in both regions r1 and r2 most popular video list. But when I searched for single most popular video in region r1 then it gives me other video with lesser number of views.

How is that possible? What's wrong here?