Using Routes External Certificate feature, 
Create 3000 routes amd 3000 secrets for that route to be used as external certificate
Delete the above objects
Recreate a few routes and secrets

We see routes go into ExternalCertificateSecretRecreated, this is not expected as the secrets were not recreated 
Looking at the router pod I see 

I0512 20:56:48.488477       1 trace.go:236] Trace[779419034]: "Reflector ListAndWatch" name:github.com/openshift/library-go/pkg/secret/monitor.go:79 (12-May-2025 20:46:50.861) (total time: 597627ms):

It looks like an issue with Secret monitor, where it is not getting the real time update. These messages loop over even though the secret had been earlier deleted
The total time also indicates this 

    4.19.0-0.nightly-2025-05-06-051838

   Always

    1. Mentioned in the description

    New Routes created are unreachable with ExternalCertificateSecretRecreated

    New Routes are reachable