BTW the Brother scare about them adding DRM that was in the news a while back turned out to be false, it was just a random guy on Reddit with a bad third-party cartridge, and Brother replied that they do not block third-party cartridges.
That said, I’m not a huge fan of their weird PPD installer on Linux that installs some random, undocumented crap
Have you checked the SMART value 199/0xC7 “UltraDMA CRC Error Count”? This should tell you how many checksum errors happened on the SATA interface between the CPU and the drive. If this is higher than zero your hypothesis is correct and there’s something bad with the connection, if it’s zero then the problem is more likely to be elsewhere.