Notable changes:

• Improves NFS performance for NFSv4 clients (NAS-139128). Adds support for STATX_CHANGE_COOKIE to properly surface ZFS sequence numbers to NFS clients via knfsd. The NFS change_info4 structure now accurately tracks directory and file changes, which reduces unnecessary server requests. Client attribute cache invalidation is also improved. Previously, the system synthesized change IDs based on ctime, which could fail to increment consistently due to kernel timer coarseness.
• Fixes NIC bonding configuration disrupted after a system update (NAS-139889). Resolves an issue where network interface bond configurations could break after a TrueNAS 25.10.2 update. Affected systems could lose network connectivity on bonded interfaces.
• Fixes SMB Legacy Share validation errors that broke share management UI forms (NAS-139892). Resolves an issue where SMB shares using the Legacy Share preset with certain path_suffix variable substitutions failed middleware validation. The SMB share configuration forms became unusable in the web interface as a result.
• Fixes API result serialization failures caused by unhandled validation errors (NAS-139896). Resolves an issue where certain Pydantic validation errors were not caught during API result serialization. This caused unexpected errors to appear in the web interface instead of proper error messages.
• Fixes SSL certificate connection failure error handling (NAS-139938). Resolves an AttributeError that occurred when an HTTPS connection failed due to a certificate error. Cloud sync tasks, replication, or other SSL-dependent network operations could surface a secondary AttributeError instead of the original connection failure message.

https://forums.truenas.com/t/truenas-25-10-2-1-is-now-available/63998