@bryce Just tried apache2=2.4.41-4ubuntu3.16 from proposed in focal, the problem is solved.
Testing done: dolphin in focal ("Konqueror/5" user agent) and jammy ("dolphin" user agent) can delete dirs over webdav endpoint running focal with apache2=2.4.41-4ubuntu3.16
@bryce Just tried apache2= 2.4.41- 4ubuntu3. 16 from proposed in focal, the problem is solved.
Testing done: dolphin in focal ("Konqueror/5" user agent) and jammy ("dolphin" user agent) can delete dirs over webdav endpoint running focal with apache2= 2.4.41- 4ubuntu3. 16