UI tabs different appearance

[The Great Maxby]

Hello everyone, 

I am currently using UI tabs inside a tab of UI tabs (i.e. UI tabs -> Ui tab -> UI tabs -> UI tab). In there I have different appearances of the tabs as shown in the pictures. I like the first appearance (picture 1), however I can't figure out why it came in the first tab but not in the subsequent ones. 
I also use the section makro with two columns in every tab but there is no difference in the settings of each column in the tabs, i.e. every tab is built the same. 

I appreciate any help. Thanks a lot. 

Best, Max