user13760: This is regarding the Buddhism SE, not its Meta.
This happened both today and yesterday. I am new to this site and I went through a lot of questions yesterday and today, and upvoted a lot. Because of that, yesterday I got the Suffrage badge for using 30 votes per day, but did not get the Vox Populi for using 40 per day, which I did yesterday. I tried the same thing today, but same result. When I viewed the progress of the badge both times after using 40 votes (I got the notification Daily vote limit reached, vote again in x hours), it showed 39 out of 40.
Is this a bug in this site only? Because I have tried this on other sites and I had no issues getting the Vox Populi there.

user254: Perhaps this is a frequently-asked question in the main Meta site --
https://meta.stackexchange.com/search?q=vox+populi+39
And perhaps it's related to something you voted on being deleted.

13760: <p><strong>This is regarding the Buddhism SE, not its Meta.</strong><br />
This happened both today and yesterday. I am new to this site and I went through a lot of questions yesterday and today, and upvoted a lot. Because of that, yesterday I got the Suffrage badge for using 30 votes per day, but did not get the Vox Populi for using 40 per day, which I did yesterday. I tried the same thing today, but same result. When I viewed the progress of the badge both times after using 40 votes (I got the notification <strong>Daily vote limit reached, vote again in x hours</strong>), it showed 39 out of 40.</p>
<p>Is this a bug in this site only? Because I have tried this on other sites and I had no issues getting the Vox Populi there.</p>
 254: <p>Perhaps this is a frequently-asked question in the main Meta site --</p>
<p><a href="https://meta.stackexchange.com/search?q=vox+populi+39">https://meta.stackexchange.com/search?q=vox+populi+39</a></p>
<p>And perhaps it's related to something you voted on being deleted.</p>
