See https://www.mediawiki.org/wiki/User_talk:IKhitron

I clicked once.

Based on testing at https://www.mediawiki.org/wiki/User_talk:Quiddity_(WMF)#A_barnstar_for_you.21 the steps to reproduce might be:

1. Go to Quiddity's talk page on mw.org
2. Open Wikilove. Choose a barnstar from the drop-down menu.
3. Press Esc to cancel. (Go do something else, e.g., scroll down the page or open a link in another tab.) (If you skip this step, then Wikilove works normally.)
4. Open Wikilove again. Choose a barnstar from the drop-down menu.
5. Press Esc to cancel. (Go do something else, e.g., scroll down the page or open a link in another tab.)
6. Open Wikilove a third time. Choose a barnstar (maybe needs to be the same as the first one?) from the drop-down menu.
7. Fill in the box.
8. Send Wikilove.
9. See two identical barnstars on the page.
10. Refresh the page.
11. See three identical barnstars on the page.

I've only tested this in Flow.