Thanks a lot! Works now!
Other bugs I found now:
If the functions.php in a child theme contains white space before or after the php tags, the arrows will keep spinning even though the vote is counted (this bug didn’t exist in 2.4, took me a while to find this).
Liked bbpress topics/replies, BuddyPress updates and blog comments don’t appear on the activity page.
The mycred hook for BuddyPress updates does not work. There other bugs in this hook but I don’t remember them all. I think points are not always deducted if you unlike content.
If you hover with the mouse over a liked user avatar, the mouse pointer flickers and for some users the link to the profile doesn’t work (I think user accounts with a first name and a last name). If you empty the file /assests/js/wp-ulike-plugins.js both problems are solved.