merge on empty Entity List gives 409 error related to properties

[lognaturel]

A user reports attempting to run client.entities.merge(entities_list, entity_list_name='my_entities', project_id=1, match_keys=None, add_new_properties=True, update_matched=False, delete_not_matched=True, source_label_key='label', source_keys=None,create_source=None, source_size=None) and receiving 409 errors. Each time they ran the call, they got a 409 on a different property.

When they added an Entity to the list, the call started working as expected.

I haven't investigated yet. This could possibly be a Central issue but I suspect it's something pyodk should handle .