@Absolute_Z 
You can use the NiFi rest-api to set the parameter context on a NiFi Process Group (PG) back to "No Parameter Context".

Example:

curl 'http://<nifi hostname>:<nifi port>/nifi-api/process-groups/<PG UUID>' -X 'PUT' -H 'Content-Type: application/json' --data-raw '{"revision":{"clientId":"a723bd7b-0185-1000-efb1-be534ab7a455","version":1},"disconnectedNodeAcknowledged":false,"component":{"id":"<PG UUID>","name":"<PG name>","comments":"","parameterContext":{"id":null},"flowfileConcurrency":"UNBOUNDED","flowfileOutboundPolicy":"STREAM_WHEN_AVAILABLE","defaultFlowFileExpiration":"0 sec","defaultBackPressureObjectThreshold":"10000","defaultBackPressureDataSizeThreshold":"1 GB"}}'

You'll notice in the data passed I have "parameterContext":{"id":null} which will clear all set parameter contexts on the specified Process Group.

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Thank you,

Matt