Comments "Like" button is missing on PR "Activity" tab but is present on "Overview" tab

There is a discrepancy in Behavior and presence of the comments "Like" button for PRs.
When you view Pull Request comments with "Overview" Tab open, you always see the "LIKE" button to like the comment of your colleague, however if you select "Activity" tab on the that same Pull request, those same comments will be missing a "LIKE" button.

Please see screen shot attached