After that i refreshed the page , and indeed his likes got increased by one (77 to 78), however, at the bottom of the post it didn't say i "liked" that post, as a result i decided to "like" him again, and well after refreshing the page his likes got dropped from 78 to 77 , so i had to wait 150 seconds before i could like him again, back to 78. In other words, the like system still works, but i and maybe other members can't see witch post they gave a like.
EDIT: I noticed that i am capable of seeing other peoples likes, just not my own.....
Solution: for some reason add blocker was blocking my own likes...