The issue is reproducible in the latest published versions of openssh carrying the patches in https://github.com/openssh-gsskex/openssh-gsskex for Ubuntu (impish), Debian (unstable), and Fedora (rawhide).
I filed a bug report in https://github.com/openssh-gsskex/openssh-gsskex/issues/20 to make sure the gsskex patch upstream is aware of this issue.
The issue is reproducible in the latest published versions of openssh carrying the patches in https:/ /github. com/openssh- gsskex/ openssh- gsskex for Ubuntu (impish), Debian (unstable), and Fedora (rawhide).
I filed a bug report in https:/ /github. com/openssh- gsskex/ openssh- gsskex/ issues/ 20 to make sure the gsskex patch upstream is aware of this issue.