Inconsistent results on GraphQL aiUserMetrics when using default timeframe

aiUserMetrics query produces different results when used with the default date range. It has a default startDate to the beginning of the month and endDate to the end of the current month. https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/app/graphql/resolvers/analytics/ai_metrics/user_metrics_resolver.rb#L107

query {
  group(fullPath: "gitlab-org") {
	aiUserMetrics {
      nodes {
        user {
          username
        }
        
        totalEventCount
      }
    }
  }
}

If the same query is used for the same timeframe, but with startDate and endDate defined explicitly, the results will be different. Example query for the current month using arguments:

query {
  group(fullPath: "gitlab-org") {
    aiUserMetrics(startDate: "2026-02-01", endDate: "2026-02-28" ) {
      nodes {
        user {
          username
        }
        
        totalEventCount
      }
    }
  }
}

When the default query without arguments is executed, the timeframe is not passed to UserAddOnAssignmentsFinder, forcing it to call current_add_on_assigned_users instead of historical_add_on_assigned_users.