A customer and I followed the instruction of the following document to change the cron schedule of whereabout-reconciler:

4.7.1.5. Configuring the Whereabouts IP reconciler schedule
https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/observability/multiple_networks/virtual-routing-and-forwarding#nw-multus-configuring-whereabouts-ip-reconciler-schedule_configuring-additional-network

The change is reflected to most of the whereabouts-reconciler pods.
However, the change was not reflected in a few pods:

~~~
[root@util ~]# oc create configmap whereabouts-config -n openshift-multus --from-literal=reconciler_cron_expression="* * * * *"

[root@util ~]# oc get pods -n openshift-multus -o name |grep reconciler |while read pod ;do echo ===== $pod =====; oc logs -n openshift-multus $pod |grep using  ; done 

===== pod/whereabouts-reconciler-798vz =====
2026-01-26T04:25:26Z [error] could not read file: <nil>, using expression from flatfile: 30 4 * * *
2026-01-26T04:27:50Z [verbose] using expression: * * * * *

===== pod/whereabouts-reconciler-fkkgq =====
2026-01-26T04:25:26Z [error] could not read file: <nil>, using expression from flatfile: 30 4 * * *
2026-01-26T04:28:20Z [error] could not read file: <nil>, using expression from flatfile: 30 4 * * *

  ===> The change is not reflected in this pod

===== pod/whereabouts-reconciler-rkmkm =====
2026-01-26T04:25:26Z [error] could not read file: <nil>, using expression from flatfile: 30 4 * * *
2026-01-26T04:28:12Z [verbose] using expression: * * * * *
~~~

I can see that the created ConfigMap "whereabouts-config" is mounted to /cron-schedule/config in the pod successfully.
It seems that the pod/application didn't detect the change of /cron-schedule/config successfully.

~~~
[root@util ~]# oc -n openshift-multus rsh pod/whereabouts-reconciler-fkkgq cat  /cron-schedule/config
* * * * *
~~~

The following logs are the entire logs of the pod:

~~~
[root@util ~]# oc logs -n openshift-multus pod/whereabouts-reconciler-fkkgq
2026-01-26T04:25:26Z [debug] Filtering pods with filter key 'spec.nodeName' and filter value 'ctlplane-0.example.com'
2026-01-26T04:25:26Z [verbose] pod controller created
2026-01-26T04:25:26Z [verbose] Starting informer factories ...
2026-01-26T04:25:26Z [verbose] Informer factories started
2026-01-26T04:25:26Z [verbose] starting network controller
2026-01-26T04:25:26Z [error] could not read file: <nil>, using expression from flatfile: 30 4 * * *

  ===> Created the whereabouts-reconciler ConfigMap here

2026-01-26T04:28:20Z [debug] event not relevant: CREATE        "/cron-schedule/..2026_01_26_04_28_20.3228436904"
2026-01-26T04:28:20Z [debug] event not relevant: CHMOD         "/cron-schedule/..2026_01_26_04_28_20.3228436904"
2026-01-26T04:28:20Z [debug] event not relevant: CREATE        "/cron-schedule/..data_tmp"
2026-01-26T04:28:20Z [debug] event not relevant: RENAME        "/cron-schedule/..data_tmp"
2026-01-26T04:28:20Z [error] could not read file: <nil>, using expression from flatfile: 30 4 * * *
2026-01-26T04:28:20Z [verbose] configuration updated to file "/cron-schedule/..data". New cron expression: 30 4 * * *
2026-01-26T04:28:20Z [debug] no changes in schedule, nothing to do.
2026-01-26T04:28:20Z [debug] event not relevant: CREATE        "/cron-schedule/config"
2026-01-26T04:28:20Z [debug] event not relevant: REMOVE        "/cron-schedule/..2026_01_26_04_25_26.4280559473"
~~~

The "whereabouts-config" ConfigMap is reflected by deleting and recreating the affected pod

We observed this issue on OCP 4.18.17 and 4.18.17

Follow the documents below:

https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/observability/multiple_networks/virtual-routing-and-forwarding#nw-multus-creating-whereabouts-reconciler-daemon-set_configuring-additional-network
- 4.7.1.4. Creating a whereabouts-reconciler daemon set
- 4.7.1.5. Configuring the Whereabouts IP reconciler schedule

And check the whereabouts-reconciler pod logs.    

The creation of whereabouts-config ConfigMap is not reflected to all whereabouts-reconciler pods

The creation of whereabouts-config ConfigMap is reflected to all whereabouts-reconciler pods