When red starts or restarts, this could be happened on a reconnect, the "Homenet" file needs to be regenerated (may the red IP-address has changed) and suricata has to be restarted to take care of the changed file.
Fixed: https://git.ipfire.org/?p=people/stevee/ipfire-2.x.git;a=commit;h=8117fff863431671939d5aa1c11c0a84e56298a2