Disk defined to the config, but image can not be found in pool

Hi,

I got the error after rebooting one of the two gateways and I can't start rbd-target-api.service

Jul 15 12:02:58 cephgw journal: Processing LUN configuration
Jul 15 12:02:58 cephgw journal: (LUN.add_dev_to_lio) Adding image 'rbd.disk_1' to LIO
Jul 15 12:02:58 cephgw journal: (LUN.add_dev_to_lio) Successfully added rbd.disk_1 to LIO
Jul 15 12:02:58 cephgw journal: (LUN.add_dev_to_lio) Adding image 'rbd.disk_2' to LIO
Jul 15 12:02:58 cephgw journal: (LUN.add_dev_to_lio) Successfully added rbd.disk_2 to LIO
Jul 15 12:02:59 cephgw journal: (LUN.add_dev_to_lio) Adding image 'rbd.disk_3' to LIO
Jul 15 12:02:59 cephgw journal: (LUN.add_dev_to_lio) Successfully added rbd.disk_3 to LIO
Jul 15 12:02:59 cephgw journal: (LUN.add_dev_to_lio) Adding image 'rbd1.disk_1' to LIO
Jul 15 12:02:59 cephgw journal: (LUN.add_dev_to_lio) Successfully added rbd1.disk_1 to LIO
Jul 15 12:02:59 cephgw journal: (LUN.add_dev_to_lio) Adding image 'rbd2.disk_1' to LIO
Jul 15 12:03:00 cephgw journal: (LUN.add_dev_to_lio) Successfully added rbd2.disk_1 to LIO
Jul 15 12:03:00 cephgw journal: (LUN.add_dev_to_lio) Adding image 'rbd2.disk_2' to LIO
Jul 15 12:03:00 cephgw journal: (LUN.add_dev_to_lio) Successfully added rbd2.disk_2 to LIO
Jul 15 12:03:00 cephgw journal: (LUN.add_dev_to_lio) Adding image 'rbd2.disk_3' to LIO
Jul 15 12:03:00 cephgw journal: (LUN.add_dev_to_lio) Successfully added rbd2.disk_3 to LIO
**Jul 15 12:03:00 cephgw journal: Disk 'rbd2.disk_4' defined to the config, but image 'disk_4' can not be found in 'rbd2' pool**
Jul 15 12:03:00 cephgw journal: Removing Ceph iSCSI configuration from LIO
Jul 15 12:03:00 cephgw journal: Removing iSCSI target from LIO
Jul 15 12:03:00 cephgw journal: Removing LUNs from LIO
Jul 15 12:03:00 cephgw journal: Active Ceph iSCSI gateway configuration removed
Jul 15 12:03:00 cephgw systemd: rbd-target-gw.service: main process exited, code=exited, status=16/n/a
Jul 15 12:03:00 cephgw systemd: Unit rbd-target-gw.service entered failed state.
Jul 15 12:03:00 cephgw journal: Shutdown received
Jul 15 12:03:00 cephgw systemd: rbd-target-gw.service failed.
Jul 15 12:03:00 cephgw systemd: Stopping Ceph iscsi target configuration API...
Jul 15 12:03:00 cephgw systemd: Stopped Ceph iscsi target configuration API.
Jul 15 12:03:00 cephgw systemd: rbd-target-gw.service holdoff time over, scheduling restart.
Jul 15 12:03:00 cephgw systemd: start request repeated too quickly for rbd-target-gw.service
Jul 15 12:03:00 cephgw systemd: Failed to start Setup system to export rbd images through LIO.
Jul 15 12:03:00 cephgw systemd: Dependency failed for Ceph iscsi target configuration API.
Jul 15 12:03:00 cephgw systemd: Job rbd-target-api.service/start failed with result 'dependency'.

The information in gwcli on other gateway.
1 gateway is inaccessible - updates will be disabled
/disks> ls
o- disks ........................................................................................................... [40G, Disks: 8]
o- rbd.disk_1 ...................................................................................................... [disk_1 (5G)]
o- rbd.disk_2 ...................................................................................................... [disk_2 (5G)]
o- rbd.disk_3 ...................................................................................................... [disk_3 (5G)]
o- rbd1.disk_1 ..................................................................................................... [disk_1 (5G)]
o- rbd2.disk_1 ..................................................................................................... [disk_1 (5G)]
o- rbd2.disk_2 ..................................................................................................... [disk_2 (5G)]
o- rbd2.disk_3 ..................................................................................................... [disk_3 (5G)]
**o- rbd2.disk_4 ..................................................................................................... [disk_4 (5G)]**
/disks> cd

The information in rbd
[root@cephgw2 ~]# rbd ls -l rbd2
NAME SIZE PARENT FMT PROT LOCK
disk_1 5120M 2
disk_2 5120M 2
disk_3 5120M 2
**disk_4 5120M 2**

I installed the package:
OS: Centos 7.5, kernel: 4.16

ceph-iscsi-cli-2.6-1.el7.centos.noarch.rpm
ceph-iscsi-config-2.5-1.el7.centos.noarch.rpm
python-rtslib-2.1.67-1.noarch.rpm
targetcli-fb-2.1.fb48-1.noarch.rpm
tcmu-runner-1.3.0-rc4.el7.centos.x86_64.rpm

I can't use ceph iscsi 2.7 because it error "ValueError: No JSON object could be decoded"

Please help me :(