SQLite Update Trigger issue

So im trying to manipulate a db using SQLite Manager. Im trying to create a trigger that updates a field, based on another field being changed, and this is what I currently have

CREATE TRIGGER staff_update
AFTER UPDATE OF c_doctor ON tickets
WHEN OLD.c_doctor <> NEW.c_doctor
BEGIN
    UPDATE tickets
    SET c_doctor_staff_contact =  doctor_staff_contact.c_doctor_staff_contact 
    WHERE NEW.c_doctor = doctor_staff_contact.c_doctor;
END

c_doctor is the name of the field in the tickets table as well as doctor_staff_contact table

doctor_staff_contact is also the name of a field in those tables as well

the duplicate naming convention was for ease of remembering for me

I've tried it with SET c_doctor_staff_contact = "test"; END and that works fine, so my assumption is = doctor_staff_contact.c_doctor_staff_contact WHERE NEW.c_doctor = doctor_staff_contact.c_doctor; END is giving me issues

Ive been looking up syntax on SQLite.org and as far as I can tell Im doing it right.