My phone's phone book used to be available in the FF.

But it's vanished. And now if someone calls me, all i can see is their number - not the name.

Is this cured by doing a 'bluetooth flash' with my IID Tool?

And, if it is, how long does the flash take? What do I put here then?

if it was there before then you need to establish what has changed since then...

Depending on your phone this can happen when you update the software (especially on iPhones).
Check in settings that ‘sync contacts’ is enabled in the Bluetooth section. 2017 Jaguar F Pace 25t Portfolio - still part of the JLR family 😀
2009 3.6 V8 (MY2010) - my first ever diesel! - now also gone
2004 4.4 V8 Petrol Vogue - now gone

Sync contacts was set to off on my phone.

So maybe it was the phone’s fault and not my FF

- makes a pleasant change

Thank you for your help. Will see if the phone book etc works tomorrow. What do I put here then?

 2017 Jaguar F Pace 25t Portfolio - still part of the JLR family 😀
2009 3.6 V8 (MY2010) - my first ever diesel! - now also gone
2004 4.4 V8 Petrol Vogue - now gone

Thank you @stan for the logic.

And thank you @chris_read for the suggestion.

Logic said my phone had been updated ...

... using the suggestion the setting is now back to what it should be ...

... and phone book in FF now perfect.

 What do I put here then?