if reading works and erasing fails that sounds to me like there is any Block Protect or similar setting.
I am trying to fix a bricked motherboard (Z170A Mpower Gaming Titanium).
The motherboard does have a MX25L12873F (not seen on your supported list) but does have the MX25L12805D and MX25L12835F/MX25L12845E/MX25L12865E as similar chips.
I am using flashrom on a Raspberry Pi 3 and had gotten quite far using the forums until I came across “ERASE FAILED”.
I am able to read the chip, but I am unable to write as it has this Erase Failed appears every time.
I’m not sure if there is a work around. I’ve seen the -f force erase but I’m not aware how to use this function.
Any help would be greatly appreciated.