My tinywhoop loses power and doesn't go up (help!)

Hey there! As the title says, something is wrong with my tinywhoop and I have no idea what can be the cause. This 8 second video shows the problem:

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https://reddit.com/link/e4hcdb/video/kive0wjiv0241/player

In the OSD you can see how I'm giving max throttle and nothing happens, usually it happens when I crash against something (air mode, horizon, stable, it's the same in all of them), but after a few mins it happens all the time even if I change batteries.

The wire where I plug the batteries (no idea the name of that part) was damaged so I thought it may be the cause, I changed it by a new one (the soldering is horrible, I don't even know how it works) but the problem stills there.

I have different batteries and it happens with all of them, maybe the cheap charger has fucked up all of them, I tried to charge one with another charger and it didn't help.

I'm about to replace all the motors, as some of them doesn't seem to work properly when I test them in betaflight, but I wanted to ask first here to see if any of you have any idea of what could be the problem :(

Thanks! :)