Only numeric type fields will be listed to be plotted in dashboard graphs. Others are not supported. There are 2 anomaly fields in message "anomaly_count" and "anomalyOutputColumn". I can see anomaly_count(number type) in list, but not anomalyOutputColumn as it is boolean.
Currently I am not able to see streaming emitter in your train pipeline, may be you have removed it. Kindly re-add it and see if you are able to see anomaly_count in list. Also there is search filter in Available Fields box to search fields on basis of keyword like anomaly.
I am removing the testDash pipeline from your work space in which I added the streaming emitter to verify.