What
When Claude Code fails to open the live connection to a remote session, it now reads a reason and extra detail sent with the failure, instead of only checking for a plain "untrusted device" message. If the untrusted-device reason is one Claude Code does not recognise, it is reported as remote_connect_unknown_sub_reason.
Why
This gives more specific diagnostics when a remote connection is refused because the device is not trusted.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
It is not clear whether these reasons are shown to the user or only recorded for diagnostics.