Translation on front-end not working

Hello, thank you for making this wonderful easy-to-use plug-in.

It seems that there’s a problem showing the translated items on the front-end. The colored boxes with Article / Articles in it don’t get translated.

I had to make the change in the child-theme to make it work.

I can see the translation of the search box on the front-end.

Is this a bug or am I doing something wrong?

Thanks in advance!
Marjon