NX300M lens oscillating in Autofocus Mode

Hello, does anyone know why the lens of the samsung nx300m keeps making these oscillations
in the footage (back and forth) .Whenever I put it in “autofocus” mode, it seems like she tries to focus on the object, but she can’t, so she keeps going back and forth several times.

You can see these oscillations in the video below (seconds 0: 08,0: 29 and 0:52)

The camera is excellent, but this defect in the focus is terrible and spoils the footage. Does anyone know if it is possible to solve this problem?
I’ve tried several types of settings and I can’t solve this problem. I used 18mm, then zoomed in 24mm, 45mm and lastly 55mm. I changed autofocus from automatic to continuous and etc.
I changed the ISO, increased the lighting, the aperture mode, the zoom, but nothing worked.
Is this a feature of the 18-55mm lens?
If so, do you recommend any other lens that is compatible with the nx300 that does not have this same problem?

Thank you!

Camera specifications:
Nx300m
Lens: 18-55m
Continuous automatic focus
Iso: 1600
1/30
Video shot in a 2mx2m room with four 25w lamps on the ceiling.

Hi @luizbrasi,

I’m afraid that we can’t be of much help with the settings of the external camera. I’d recommend checking out the forums and discussions solely dedicated to working with different lens and cameras.