Identifying Device Type

I am very new to Fing and an amateur at networks so please forgive my naive questions. When I set up my devices were detected — sort of. Out of three iPads only 2 were correctly identified. Out of three iPhones none were identified. The ip addresses were detected but the devices were identified as being generic. I worked out which is which by ping testing when each device was on then off. I could then lable them correctly. Have I missed something in the setup or scan that would/should detect manufacturer and model?