Sysfn 76 returns -1 for a missing device. The ARP conflict counter check in .maintain_link treats any change of the value as a new conflict, so when a device disappeared the counter jumped 0 -> -1 -> 0 across the reconnect and a bogus "IP address conflict" notification popped up on every replug of a USB network device. Skip the check when the query fails. Assisted-by: Claude Opus 5 <noreply@anthropic.com> Reviewed-on: KolibriOS/kolibrios#677 Reviewed-by: hidnplayr <hidnplayr@gmail.com> Reviewed-by: Burer <burer@kolibrios.org> Co-authored-by: leency <lipatov.kiril@gmail.com>