Workflow rule not triggering on field update through API

Workflow rule not triggering on field update through API

We have a workflow rule that should trigger when a project's custom Boolean field is marked as true. If this field is marked true manually by a user, the workflow triggers as expected. We have a Zoho Books function that updates this field on a certain criteria but when the custom Boolean field is updated through the API call from Books, the workflow does not trigger. Has anyone else experienced this and is there a way to fix it? Thanks.