Have changed the Y axis column on a chart which appears in a pre-existing dashboard. However, this updated chart after save does not seem to pull through to the dashboard. Is there any reason why the chart would not be updating in the dashboard?

Have changed the Y axis column on a chart which appears in a pre-existing dashboard. However, this updated chart after save does not seem to pull through to the dashboard. Is there any reason why the chart would not be updating in the dashboard?