Apologies, this was due to the TPM not being properly cleared beforehand, which required a manual activation in the BIOS. Once that was done, the PS command worked properly.
TPM Activation appears to not be working either. Failed on XPS 13, OptiPlex 9020 and OptiPlex 9020M. Enabling and turning on appears to work without issue. And yes, a password is set and supplied during activation attempts. CCTK accomplishes the task without issue.