Locked-NVram sometimes refers to Trust security settings.
I see that you have already disabled TPM but there may be another sub menu with other options?
Can you have a look around your UEFI settings and see if you can disable anything similar to below:-
- TPM (Trusted Platform Module)
- PTT (Platform Trust Technology)
- FTPM (Firmware Trusted Platform Module)
- TPT (Trust Platform Technology)
- PSP (Platform Security Processor)
- Device Guard
- OS Optimised Defaults
- Lock UEFI BIOS Settings
- Boot Order Lock