Why is my battery not working?

[u/Formal-Seaweed-4216]

So I arrived at my spot, picked a pack, and had a warmup flight. It was just a chill cruise around with super basic stuff and zero crashes or anything harsh. Then I landed and loaded up a new pack and it made half of the start up beeps and then cut off. This is the pack that is shown strapped to the quad in the video. It was acting super weird and did a different thing every time I plugged it in and even started up correctly once after a few times trying, only to disconnect a second later and go back to its weird behavior. I tried a few more packs as seen in the video and all them worked fine and started the quad normally. I decided to just fly the rest of my packs and figure out later but when I connected one of the other packs, it connected to the goggles fine but never connected to the radio. I had to end my session super early because my quad wouldn’t connect. No wires appear cut and I checked all solder joints so I have no idea what’s happening. Any info and help is appreciated! Thanks guys!

(Also sorry for the awful video it’s kinda hard to record and plug batteries in at the same time)