Hi eyhylee
Does this happen on live TV? Does this happen when using apps, or On Demand, or Catch Up Services? Loss of picture and/or sound can happen on live TV, but it's usually experienced on apps such as Netflix, Prime and Disney+ and is generally due to a difference in frame rates.
On the 360 go to Settings >Audio & Video > Match frame rate
If it's set to ON then people do see a blackout/or hear a sound drop when the 360 or HDMI reconfigures for the difference in frame rate.(This is more noticable on live TV when switching from adverts back to a program, or changing channels)
If it's set to the default (OFF) then the box just accepts the frame rate difference which isn't noticeable by most users and shouldn't blank the screen out. (Either way try toggling this setting to see if it solves your issues)
Have you tried a different HDMI cable and/or different HDMI port? Some Samsung TV's provide an HDMI Cable Test within the TV's support menu. Navigate to Settings > Support > Self Diagnosis > Signal Information > HDMI Cable Test.
Are you using Samsung's One Connect box? If so please check the following page /samsung/support/troubleshooting/TSG01109749/#tv-with-a-one-connect-box-has-no-picture