minimum processor state is locked

For my HP laptop, the minimum processor state is locked. For Balanced, it's at 15%. If i change it, it just goes back to 15%. Is there a workaround for this? Thank you.

You cannot force a CPU to go to minimum processor state less than its rating, base speed and speed step range.
You will have to look at the detailed specs of your CPU.

e.g. the lowest speed step on the CPU in my old Laptop is 32%, you can set the minimum processor state to less than that sure, but it will not do it.
Similarly for the new Laptop is 17%.

On both the minimum default is 5% as set in Power Options. You can set values like 50% or 100% and it will do that, but the lowest depends on CPU specs.

Depending on your CPU, you could try an undervolting software, but for starters: