Hey there, I have a 2018 Honda Fit EX. Last night, while parked in my driveway, the car started freaking out, headlights coming on, going off, dash lights flickering on and off, clicking noises, car would not start. We thought maybe the cold whether had finally caused the battery to fail. Car was dead in the morning. Hooked up jumper cables, car would still not start, but got enough power for wife to connect her code reader, and it indicated the battery was bad. We went out, got a new battery, put it in the car. Power came back on as normal, but when we tried to start the car, the immobilizer system seems to have been triggered. Flashing green key symbol, along with the keyless start error symbol. Now the car seems to not recognize either of our key fobs. Tried to research it, but so far nothing we have tried has resolved the issue. Ideas?

Tried working the physical key in the door 8 times, that did not work. Tried disconnected the battery for five minutes, reconnecting, same result. At one point, while sitting in the car for a significant time period not trying anything, I pressed the start/stop button to turn the car off, and the car did seem to turn off completely... and after about 30 seconds, the immobilizer light also went out, and suddenly the lock/unlock buttons on my fob were working again! So, I pressed the brake and tried to start the car again... and the immobilizer light immediately came on again, and my fob buttons also stopped working again. Can someone help me solve this mystery?