[Plugin: Digg Digg] Likes disappear after few secs

I have manualy added like button just next to the post title in the archive… The problem is that after I push the Like button it actualizes, shows the number or that I like it and then…back to previous state, a matter of 1 second and I can Like it again. What can be wrong? I have tried every type of like button and the same thing happens, link: https://koleba.pl/word/category/zupy/

https://www.ads-software.com/extend/plugins/digg-digg/