Hello,

check out the corresponding operating instruction manual of your drive.
The following link is to the CU240E-2 operating instruction manual which shows in chapter 7.1 which parameters can be changed even with active write protection.
https://support.industry.siemens.com/cs/ww/en/view/109782865

Parameter p0970 is accessible, so you can`t prevent the parameter reset itself.
But maybe you can use a memory card and the write protection of the memory card to make sure that after every power cycle the drive will come up with the defined setup. The drive will load the parameter set which is stored on the memory card during booting.