i have the same issue and had my unit for 4 months one service call and they replaced the fan. worked great for two days and noise is back. had another service ticket and they guy went through some steps and said it should get better but nope. i will call samsung again to complain.
Reviving this thread, have a four flex fridge, and suddenly, after the warranty ended, started hearing this noise. Thought it was the ice build up on the fan inside, checked that, nope. Started to run around the fridge when I heard it again (which is every couple of hours) and found it coming from the rear bottom left (if facing the back), took the shielding off and found it was coming from the compressor (Samsung part# nc1mv90alp). It's extremely annoying/loud, didn't do it the first year, at all, and wondering if any fix? I see this post says "solved" but then, directly under the post that mentioned the solve, the OP writes that didn't solve it, so wondering if there is any other advice?