Duplicate Rules Settings are only respected on form level and not when editing records in the editable grid.
Even when specific features are deselected (like "When a record is created or updated" and "During data import"), every update on a record via Editable Grid triggers ALL active duplicate detection rules.

Contacts can not be saved until this issue is resolved. Being designed as a form to quickly edit contacts/records, this makes working with editable grids a little cumbersome.