I want to implement BitLocker on several computers throughout our network. I created an OU and GPO to pull the Recovery Key's to AD, this worked fine. However, I want to use 4 digit PIN's for the devices rather than Passcode's. I have Dell's that ask for a PIN when setting up Bitlocker but my Lenovo ThinkPads only ask for Password or USB set up. I have tried to use powershell after encryption to convert to PIN but it says "Theres already a passcode protector on the drive."

The Lenovo's are ThinkPad T470s

- - - Updated - - -

I believe this is caused by MBR. Our deployment process requires this. So I ran mbr2gpt in order to fix it. I am then able to use a PIN.