Header image no responsive in "boxed"

Hello everyone,

i have a header photograph (photo of logo and name) that is the proper 1200 x one hundred fifty px size. It scales, as does the slider and widget photographs, flawlessly whilst in “huge” mode. but as quickly as I transfer to “Boxed” mode inside the Nirvana header settings (with “force responsiveness” enabled), it now not scales responsively. the alternative photographs preserve to paintings perfectly, just not the header graphic in “boxed.” How can i restore this? My patron prefers the boxed mode but we want that header photograph to scale.

Thanks in advance for help!