Hi there Paulo,
flashrom v0.9.9-unknown on Linux 4.14.98-v7+ (armv7l)
This flashrom version is probably very outdated, and we don't know if the same problem exists in the latest flashrom as well. Please, could you get the latest flashrom sources (e.g. git clone https://review.coreboot.org/flashrom/ , build them using the instructions here - https://www.flashrom.org/Downloads#Installation_from_source , and try again?
Best regards, Mike Banon