AD8232's IAOUT has some random noise

I bought AD8232 EVAL and checked ECG signal under the following configuration.


3 electrode connection

DC leads off detection

FR disable

During measuring ECG signal on IAOUT and OP AMP OUT, there are random noise on both signals as the following pic. It looks like IA malfunction. Is it normal behavior for AD8232?

Actually the other ECG monitor solution which is used AD8237 and AD8607 has no problem under same condition.

Moreover there is a lot of hum noise (50/60Hz noise) on it too.