Lumia 640 Unable to turn on Bitlocker

[redpowerranger]

Hi,

I am trying to enable Bitlocker on a Lumia 640 which has the most recent Windows 10 Mobile update applied.

I have enabled Bitlocker in Upadate & Security >Device Encryption but when I check the System>Storage for confirmatiion there is no mention of Bitlocker.

Does anyone know of something I can try please?

thanks,
James