MAC address is always spoofed temporarily since it's a read-only number burned-in hardware and a part of it uniquely identifies the manufacturer. However many network interfaces allow setting a spoofed address. In order to make the change permanent the overriding process has to be repeated on every boot.
Secondly, configuring network interfaces requires at ...
FYI, for future readers, I believe the correct way to disable this feature is by going to:
Settings > General management > Language and input
Then, under "Input Assistance," set "Autofill services" to "None."