Glitch - Action bar's empty slots are shown
 

Hi, so when I switch abilities between slots the empty slots are shown, as it must be. My issue is that sometimes the empty slots REMAIN shown after I finished switching, remaining all of them visible (I added a screenshot in this post).
I remember when I used to play a year ago I was able to hide them again, but for that I was mean to change some abilities from place to place but I can't remember how ;(
Please help

https://imgur.com/a/9SI4U3g

I think you can find them in the bartender options /bt