pagination toolbar vibrating (weird beahavior)

オフライン

hello 

I'm having issue with the toolbars you can find at the bottom of relationship tabs on different types of items this toolbar help navigate through the different pages of related items. The issue is visual, the toolbar is vibrating up and down really fast. i get this behaviour when i open an item that has relationship tabswhen i first click a tab the tool bar is vibrating but if clik an other one and go back at the first it stops vibrating. other thing is when the vibration is happening at certain zoom level (vibrating from 67% to 75% ).

Here is the toolbar i'm talking about:

thanks,

Lucas