My 2015 13" Macbook Pro's keyboard and trackpad no longer work and I've already replaced the connector flex cable twice. That worked for a few weeks but after the third replacement they keyboard and trackpad no longer work (I assume the new flex cable works).
Interestingly, the keyboard and mouse work just fine when I boot from an Ubuntu live USB stick. In a youtube video by Louis Rossmann I can no longer find he mentions this may be due to the Macbook being connected to the keyboard and trackpad via USB by default. Something in the connection/USB controller may be damaged and Ubuntu can fallback to SPI to connect to the keyboard and trackpad whereas MacOS lacks drivers for this.
My question is whether a) how I can test this hypothesis and whether there may be a driver for MacOS that can connect to the keyboard via SPI and b) whether I can otherwise avoid replacing the entire keyboard/trackpad/battery ensemble.
Thanks for any help!