Redrawing chart changes y axis maximum

I have a table which drills down to change a chart:`MS_DDI_Microservices` metric_name="Rate:Exchange:*" | rex field=metric_name ".*:(?<Exchange>[^:]*):(?<direction>[^:]*)$$" | chart avg(Average) by Exchange, direction$time.earliest$$time.latest$1$refresh$$row.Exchange$20nonecellfalsefalsefalsetrue`MS_DDI_Microservices` metric_name="Rate:Exchange:$exchange$:*" | rex field=metric_name ":(?<direction>[^:]*)$$" | timechart avg(Average) by direction$time.earliest$$time.latest$1$refresh$collapsedcollapsedcollapsed1lineconnectright When the dashboard draws initially the chart has a y-axis that just includes the data (currently 7.5). When I select a row in the table the chart redraws with the y-axis up to 100, well over what is required. Selecting back to the original row keeps the y-axis maximum value of 100, which renders the data as a tiny curve at the very bottom of the chart. Any thoughts? I've left the y-axis max at the default, documented as auto. I think it works right the first time but not afterwards. Splunk Enterprise 6.6.2