fbprophet for anomaly detection giving different results on same data

I am using fbprophet for anomaly detection, and for the same data sets, the results are different for different runs in my laptop. The number of anomalies and the anomalies which the code pick up are different for 1st, 2nd third.. runs. I am confused, how can I use this , though it is giving good results many a times. The false positives are too many in a few runs.
Can someone please help me to fix this.
I have tried algorithm = 'Newton'. Still the result is not constant.
Sree