Cannot delete clef

Hi there. When I delete the superfluous treble clef it gets supplanted by a nonsensical bass clef that I cannot get rid of. Any ideas how I can delete the offending clef? Thank you.

Welcome to the forum, Geoff. What are the two instruments here? You’re switching to a Clarinet in B flat, but what are you switching from? In general Dorico won’t show redundant clefs like this at instrument changes, but there is a subtle problem whereby an instrument that uses a different clef in concert and transposed pitch can end up incorrectly showing a redundant clef in the transposed layout, though this is (so far as I know) fixed in Dorico 3.5.