Migration Required for blank Sensitive Properties Key [nifi.sensitive.props.key]

[#1]

I have posted this question on SO too, here.

Summary:

I have docker file(based on official docker file for apache nifi 1.22.0).

When I launch a container first time, all works fine.

But for subsequent launches, I have to remove volumes, else I get error. 

2023-08-28 03:01:14,845 ERROR [main] o.a.nifi.properties.NiFiPropertiesLoader Flow Configuration [/opt/nifi/nifi-current/flow/flow_configuration/flow.json.gz] Found: Migration Required for blank Sensitive Properties Key [nifi.sensitive.props.key]
2023-08-28 03:01:14,845 ERROR [main] org.apache.nifi.NiFi Failure to launch NiFi
java.lang.IllegalArgumentException: There was an issue decrypting protected properties

I already have following in start.sh:

if [ -n "${NIFI_SENSITIVE_PROPS_KEY}" ]; then
    prop_replace 'nifi.sensitive.props.key' "${NIFI_SENSITIVE_PROPS_KEY}"
fi

So what is bugging my setup?