I’ve recently been encrypting our fleet of Dell XPS 13 laptops ready for GDPR compliance come May 2018. I have had some issues with the machine asking for the bitlocker recovery key on each startup and from what I can tell this involves a TPM level 2.0 being used when Secure boot mode is off and Legacy boot options are used. A TPM 2.0 does not like secure off and legacy boot options, so I found the solution (for me at least, on Dell XPS 13 9360 units) was to use the Dell TPM Switcher Utility and downgrade the TPM from 2.0 to 1.2. This has to be done from Windows, but I found disabling Bitlocker, downgrading the TPM, and then enabling BitLocker resolves the issue.
