Tabsheet tabs with long captions

I discovered a weird behaviour using tabs with long captions. The normal behaviour should be that if the tabs in a tabsheet are not fitting the space the scroller becomes visible. My problem is that the scrollers are not visible/not getting rendered. They become only visible when clicked the last visible tab.
See attached images.
tabsheet before
shows the weired behaviour.
tabsheet after
shows tabsheet after selecting the last visible tab.

Does anybody else got this bug?
Used Vaadin version is 7.5.9. The same behaviour is occours in Vaadin 7.6.x.

30803.png
30804.png

I think this one is the same bug, it has been fixed in 7.7.0.

https://github.com/vaadin/framework/issues/7752

Thanks Tatu for your reply. First i was thinking that could be the issue but after an update to 7.7.7 the weird behaviour still exist. I made a small screen recording which shows the bug.