Voice count on reviews showing Zero

[anand.au14]

On the Plugin Reviews list, it shows a Voice count column. This column displays the number of users involved in the conversation including the reviewer.
If no one has responded to the review yet, it shows count 1 for the reviewer.

I just noticed a strange behaviour where it is showing zero for the voice count of 2 non-responded reviews. While for the similar one it is showing 1, which is correct.
You can check it here ​https://wordpress.org/support/plugin/wp-mail-log/reviews/

I have attached the screenshot.

[Ipstenu]

I'm moving this to Support Forums because that's actually not the plugin directory code.

Also FWIW there's a LOT of caching that goes on, and many counts are peculiar but ... I see the counts correctly as myself (an admin) and a private window as a non-logged in user.

Are you sure this isn't your browser?

[anand.au14]

I have checked it on multiple browsers and on two different systems.
Also, not all reviews are showing this behaviour. As you can see in the above-attached screenshot, the first one is showing the correct count - 1. But the next two are showing zero.

Also, they are not any recent reviews, they are more than one month old. So I don't think there can be any database cache.