Does educational research productivity count as research productivity?
Different schools will weight publications differently. DBER research is often seen as less rigorous than other research, and often is less rigorous than similar research conducted by education scholars. (DBER often uses samples of convenience and has limited ability to randomize treatments; this still can generate valuable insights, and is often the limit of what active biologists (say) can make time for, so peer-reviewed journals are not going to insist on only the most rigorous methods.)

Beyond that, the fact that your primary research is closely linked to your DBER is very helpful. Grants that ask for the external impact of your work will look favorably on a record of translating your work into advances in education.