Either way, it's been resolved. Thanks Hazink!
Are you sure?
In seriousness, it could have been my memory (which it was)
I haven't noticed any memory problems in you. I looked at your behavior. It's hard to call you generous. I can say for sure that you don't hand out merits just for. You are read each post carefully before handing out merits.
I have no idea what type of AI Theymos has coded in.

Are you finished with the ceremonies and congratulations? Can I speak out now?
It's an old bug in system.
You probably immediately refreshed the page from where the merit was posted after sending the merit. After each page refresh, the merit will be written off from you and sent to the user whose post you liked. But your specific case also showed that the bug can behave quite unpredictably and write off merits not only for the same post.