beem.snapshot.AccountSnapshot.get_data returning all zeros

[jemshid]

 import datetime as dt
 acc_snapshot = AccountSnapshot("holger80")
 acc_snapshot.get_data(timestamp=dt.datetime.now(tz=dt.timezone.utc))                           

This returns

{'timestamp': datetime.datetime(1970, 1, 1, 0, 0, tzinfo=<UTC>),
 'vests': 0.000000 VESTS,
 'delegated_vests_in': {},
 'delegated_vests_out': {},
 'sp_own': -0.0,
 'sp_eff': 0.0,
 'steem': 0.000 HIVE,
 'sbd': 0.000 HBD,
 'index': 0}

The get_data method is expected to return current balances as of now, but is returning zeros and the timestamp taken by the method is the old 1970 date, which is the default.

[jemshid]

In [18]: acc_snapshot = AccountSnapshot("bobinson")                                                     

In [19]: acc_snapshot.get_data()                                                                        
i: 1
index: 0
Out[19]: 
{'timestamp': datetime.datetime(1970, 1, 1, 0, 0, tzinfo=<UTC>),
 'vests': 0.000000 VESTS,
 'delegated_vests_in': {},
 'delegated_vests_out': {},
 'sp_own': -0.0,
 'sp_eff': 0.0,
 'steem': 0.000 HIVE,
 'sbd': 0.000 HBD,
 'index': 0}

Another case