NHTSA Complaint #11457667 — 2020 JEEP COMPASS

I purchased this vehicle a year ago. About 2 months ago I started having problems getting the vehicle to start. AAA & Geico have come several times to jump me. The vehicle also states High coolant temperature sometimes when it does this. At one point it would not go over 35 mph. I took it to the jeep dealer to be told start by replacing both batteries for $600 and then we can go from there! She also stated it was probably electrical. I don't have $600 to spare, especially on a vehicle that's a 2020. Took it to Auto Zone they tested both batteries & said they both tested fine. I ended up purchasing a jump box as this happens at least 3 times/week. Well as of today, now that wont even work.