PTT is a way of provider TPM, they are not two separate things. PTT is a non-dedicated hardware approach to TPM 2.0. PTT is designed for low power devices, often used in industrial computing.
Traditionally TPM requires a TPM module, a dedicated hardware processor and firmware for security. With TPM 2.0 dedicated hardware is no longer required. PTT is Intel's implementation of TPM 2.0 for low power systems.
@coliver Did you setup a Microsoft account on them?
No domain joined machines.
Are you sure Bitlocker isn't on, just not activated?
I'm not sure what you mean? Bitlocker is a part of the operating system... you need to turn it on to enable encryption. So if you're asking if it is installed the answer is yes. If you're asking if it is enabled the answer is no.
Bitlocker has three states, as far as I can tell
Bitlocker On, but not activated - not encrypting drive
In my experience, a BIOS based machine puts Windows 10 into option 1 above.
My recent experience has shown that machines with UEFI and Secure Boot enabled that Windows 10 puts the system in option 2 or 3 depending on setup.
If you add a Microsoft Account while going through OOBE, the Windows will create a recovery key for Bitlocker, save it to your OneDrive account, and use option 3.
If you add a local account during OOBE, Windows will put the system into option 2.