I remember watching a short film years ago about a time loop where there's this guy in a white plastic onesie with goggles, almost like a CSI worker. It starts with him in a room behind a chair I think and it ends with him jumping off a building onto a safety mat. He tries to avoid other people throughout and it turns out the other people are him in other loops.
I think you are referring to "Mouse X", a sci-fi short movie by Justin Tagg, created in 2014 and available on YouTube:
All of your described details fit (white suit with goggles, trying not to be seen, jumping onto a mattress). He does not start out behind the chair, but waking up on an armchair, but a later scene reveals that another version of him is, at that moment, hiding behind that very armchair.
I am just not sure whether the person is in a time loop, or whether there are actually many copies (clones?) of him in a carefully arranged environment that lets all of them always make the same choices over and over.