Empty data in rrd graph - someone could chk my config?

Hi all, could someone verify i did this right please, my item is passing temp data just fine via MQTT, though in my rrd file i see only 0’s and the graph shows no data :frowning:

Number isaacs_temp "Isaacs Room Temperature [%.1f °C]" <temperature>
        { mqtt="<[openhab:tele/sonoffsingle1/SENSOR:state:JSONPATH($.DHT22-14.Temperature)]" }
Strategies {
//rrd chart stuff
everyMinute:"0 * * * * ?"
Default = everyChange
Items { isaacs_temp : strategy = everyUpdate, everyMinute, restoreOnStartup }

2017-12-29 14:40:30.013 [WARN ] [el.core.internal.ModelRepositoryImpl] - Configuration model ‘rrd.persist’ has errors, therefore ignoring it: [5,1]: no viable alternative at input ‘Default’

saw the above in the logs, changed the rrd.persist line default - using lowercase ‘d’ gets the config loaded.
will report back if that fixed it.