Unwanted clef change in ossia

I created an ossia bar in a cello part that has been in tenor clef from the very beginning of the piece. Dorico placed the ossia in bass clef. When I changed the ossia bar to tenor clef to match the main part, Dorico also added a tenor clef sign and a key signature, which are unnecessary and distracting. Is there a way to prevent Dorico from second-guessing me about what clef I’m writing in?

A new ossia staff will use the default clef of the instrument; it won’t assume that it should use the same clef as the existing main staff. What I would suggest is temporarily showing the ossia right at the beginning of the flow, and changing the initial clef from bass to tenor at that point. Then hide the ossia again at that point (by deleting the signpost that brings it into being) and when it later reappears at the point you actually want it, the tenor clef should already be in force.

Daniel, thank you. Suspecting that, as another type of extra staff, divisi would act the same as ossia, I followed your advice and solved a problem I had been having on a current project. So again, thank you.