Still works after downgrading to

openbolt=5.4.0-1+debian13

. Re-reading the scrollback, you mentioned hardening --- so settings in

sshd_config

are definitely relevant. Also, if there is a standard or benchmark that you are using for hardening, a link to the requirements of that would be helpful. E.g. if Bolt doesn't work out of the box with something like CIS, then that would be good context.