Hi Lalo. I'll skip right past the "what is this" part that you didn't ask about...and answer what you DID ask - "has anyone ever heard of this before"? Well, more like, experienced this before. When I get emotionally overwhelmed, or emotionally exhausted, my mind takes breaks similar to what you are reporting. How it presents, what happens when it does, varies, for me. It can run from being on auto pilot (going through my day without much conscious thought of what I'm doing) to completely blacking out and having no memory of anything (sometimes finding myself in places with no memory of having gotten there, or time loss) - to even having different memories of time and events than those around me report (thinking I'm at home...others telling me they saw, even interacted with me, elsewhere).
The ironic part is, I knew I experienced this, and then while in therapy, I learned I was doing it way more than I even knew. The good news is, there are techniques you can learn, to help yourself in those moments. You can learn how to recognize when it is coming on,...and stop your mind from stepping away from your body. You're not alone, and a good therapist can help you explore this, and hopefully even get a handle on it.