Notice that a majority of issues are the low strung. This is where you “palm mute”. On my Godin XTSA either my low A or E goes out. I believe my sweaty hands salts are causing this. It is a pain but this is how I’ve fixed twice over many years.1)Remove strings 2)Remove back cover behind knob controls 3)Carefully unpack small bunch of cables. These goto the piezos. 4) Remove piezos and using the cables and NOT the piezos, gently and carefully pull the piezos away from bridge. 5) Next fill cup with DISTILLED water and slosh the piezos in the water. Let them set and change water and slosh again. Do 5 times. We are trying wash away the salt from the hands. 6) Dry piezos with paper towels and hair dryer on warm. Plug in guitar and gently tap each piezos. If one is not working clean it again perhaps using the water and a soft toothbrush. 7) Gently re-insert cable back in. 8) Attach piezos to bridge.9) install string and re-internate. Pain to do but has worked twice for me. Next time I may paint piezo with clear fingernail polish.