I need some help with basic things

I wanted to animate character but then something really weird happened …

So I tried to recreate my steps on a basic cube and I also recorded a video to show you what happens when I try to animate negative values

Basically I set the object to start from 0 rotation after few seconds to rotate to -20 degree and after another few seconds to get back to 0

But after I set the value of -20 Unity automatically sets my value to 340 so my cube has to make full circle

There is also a solution but … it won’t help me at all if your object starts from -1 and goes to -20 the goes back to -1 there is no problem but I work with a lot of children objects so that’s a big problem.

- YouTube forgot to post the video