2020 Mitsubishi outlander sport ES with 2.0L engine. The battery is an interstate group 35 battery with a 450 CCA rating. Lately I've had problems with an intermittent starting issue. I've tested the battery for voltage and also put a load on it and tested and my meter showed the battery to be weak under load. The voltage started out at 12.1-12.5 VDC, but then dropped to 7.6 VDC and the battery did not start the engine. I used a jump pack to give it a little boost and was able to start the car. I took the car to my local interstate battery store and had them test the starter and alternator along with the battery and their tester showed everything was working properly. I felt like I was going crazy. I had 2 more incidents where I had to use the jump pack to start the car. I took the car to AutoZone and had them stick their tester on it and it showed the alternator was bad. It's now been 2 weeks and I haven't had any problems starting the car at all. I haven't replaced anything at this point, but I'm here to see if anyone can tell me what may be going on. Everything I've checked says that I should have a higher CCA rating on the battery in my car. The battery is about 1½ years old btw.
Is there something I'm missing here or is my car possessed?

 

The first sign of trouble came when my car occasionally failed to start. At first, I assumed it might be an issue with the starter or the alternator, but as the problem became more frequent, I decided to test the battery to rule it out.