TypeError: bad operand type for abs(): 'NoneType'

[sentry]

Sentry Issue: EXPERIMENTER-PROD-16X

TypeError: bad operand type for abs(): 'NoneType'
(2 additional frame(s) were not displayed)
...
  File "experimenter/nimbus_ui/views.py", line 854, in get_context_data
    extreme_bound = results_manager.get_max_metric_value(
  File "experimenter/jetstream/results_manager.py", line 103, in get_max_metric_value
    max_value = max(max_value, abs(lower), abs(upper))

┆Issue is synchronized with this Jira Task