Seems obvious,and done it for years, delete and the gap is gone. Since I have moved from Ubuntu to fedora 42, this doesn’t work any longer. I can delete, cut, whatever, but the gap remains. Google (KI) says Ctrl+X. But also this doesn’t. The content is gone, but the gap stays. There is a Remove Special, but it only offers Cut and Delete, both with “and leave gap”.
Audacity 3.7.4