HeaderCell remove my styles (7.6.0.alpha7)

I customized my HeaderCell using setStyleName and define my style in my theme scss file. Everything is working fine.
Recently, I upgraded from 7.6.0.alpha2 to 7.6.0.alpha7 and every style I've defined is not showing.
Then, I reverted back to 7.6.0.alpha2, it's showing properly again.
Is it bug or there are changes of coding method? Thanks.
 

ticket submitted: https://dev.vaadin.com/ticket/19209

still exists in 7.6.0.rc1
no one care to look at this bug?

It seems that the DOM structure has changed a bit between versions:

alpha 2:

RC1:

In order to get the same styling you'd need to apply the CSS to the th above the div instead of referring to it directly. This is indeed a bit problematic, in my opinion the custom style name should be applied either both elements or just the top element. 

hi, thanks for confirm this bug.
so what the best should I do? waiting for fixes or doing the workaround?
could you elaborate more about your workaround? I'm not quite understand about it.

Well, as Artur stated in the Trac ticket, this is a regression and there isn't a real workaround for this issue. But as this is trivial to fix there will most likely a fixed version soon.

Thank you for reporting the situation :)