Issue FieldInput complains about 'data was not an array'

Hi community,

I’m using Jira Java REST API to create issues, while encountering custom field errors when filling the issue input. Here is my code snippet:

IssueInput issueInput = new IssueInputBuilder()
                .setProjectKey(jiraTicket.getKey())
                .setIssueType(templateIssue.getIssueType())
                .setDescription(description)
                .setComponents(templateIssue.getComponents())
                .setFieldInput(new FieldInput("customfield_20203", ComplexIssueInputFieldValue.with("value", "Medium")))
                .*setFieldInput(new FieldInput("customfield_20205", ComplexIssueInputFieldValue.with("value", "Production")))*
                .setSummary("creating new "+cicdComponentType+" project for "+jiraTicket.getProject().getName())
                .build();

And the error log:

SEVERE: Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is RestClientException{statusCode=Optional.of(400), errorCollections=[ErrorCollection{status=400, errors={XXX=data was not an array}, errorMessages=[]}]}] with root cause
RestClientException{statusCode=Optional.of(400), errorCollections=[ErrorCollection{status=400, errors={XXX=data was not an array}, errorMessages=[]}]}
	at com.atlassian.jira.rest.client.internal.async.AbstractAsynchronousRestClient$2.apply(AbstractAsynchronousRestClient.java:176)

Can you guide me here how to fill this field ‘customfield_20205’, which seems requires an array type inputs?

Thanks,
allen