When syncing members in bulk via the Lists endpoint, tags are now properly added to existing members. If you would like to completely replace the tags of a member with the tags being passed in the request, we have added a new boolean param sync_tags, which will cause the call to replace any tags on the existing member. This will only work when making the call with updated_existing set to true.

Previously, when updating members in bulk via the Lists or Members endpoints, tags would not be added to an existing member. There was also no way to overwrite the tags completely.