Ebay Sandbox: The filter=conditionIds filter value is invalid

[bekindpleaserewind]

When specifying any conditionIds as a filter in the eBay sandbox buy browse api, it fails with the following returned error.  This works in production just fine.  I have tried different valid conditionIds, no combination works:

{'category': 'REQUEST',
'domain': 'API_BROWSE',
'error_id': 12002,
'input_ref_ids': None,
'long_message': None,
'message': 'The filter=conditionIds filter value is invalid. For the valid '
'values, refer to the API call documentation.',
'output_ref_ids': None,
'parameters': [{'name': 'fieldName', 'value': 'filter=conditionIds'},
{'name': 'filterValue', 'value': '{2750|3000|4000|5000|6000}'}],
'subdomain': None}