Problem with pingback

I participate at the Weekly Photo Challenge, but my pingback doesn’t appear on the Daily Post.

Sorry? Can you elaborate on this?

Every week, https://dailypost.wordpress.com organizes a photo challenge. When I participate, I post a picture on my website, with a link to https://dailypost.wordpress.com. For example, this week I put a link in my post to https://dailypost.wordpress.com/dp_photo_challenge/extra-extra/. Normally, I see a link on https://dailypost.wordpress.com to my post on my website and my post is listed as well. Since one week, this doesn’t function anymore?

Perhaps you need to ask the folks over at wordpress.com about this?

Okay, will do so. Thx!

I have contacted wordpress.com, but they referred me back here. I don’t know what to do. I have enabled pingbacks on my site, but it simply doesn’t work. I really don’t know what to do???