Chronograph failed on tick from round

Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/prozorro_sale/procedure/models/types.py", line 135, in __getitem__
    return super().__getitem__(key)
KeyError: None

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/auction/prozorro_sale/auction/chronograph.py", line 38, in chronograph_loop
    auction.timer_tick()
  File "/auction/prozorro_sale/auction/state_machine.py", line 153, in timer_tick
    self._auction.set_state(self.next_state)
  File "/auction/prozorro_sale/auction/state_machine.py", line 629, in set_state
    state_new.onEnter()
  File "/auction/prozorro_sale/auction/state_machine.py", line 180, in onEnter
    self._set_bid_hints()
  File "/auction/prozorro_sale/auction/state_machine.py", line 201, in _set_bid_hints
    initial_bid_amount = self._auction.initialBids[bid.id].value.to_primitive()['amount']
  File "/usr/local/lib/python3.8/site-packages/prozorro_sale/procedure/models/types.py", line 137, in __getitem__
    raise ObjectNotFound('object', key)
prozorro_sale.procedure.errors.ObjectNotFound: Not found object object with id None
[2020-05-08T09:30:00 +0000] | prozorro_sale.auction.db | INFO - Processed auction 5eb51d38701dbdf37400cd42, time - 0.03324484825134277 | X-Request-ID: None

Ref issue: auction-frontend#74 (closed)