I have just started to notice this, the ads have become quite intruisive. This was a top of the range TV costing thousands - having ads in the menu is tacky and irritating, and it has started to get in the way of menu navigation! I would not have purchased this TV if I had known about this; adverts belong in content (where they can be skipped, or paid to avoid) - not on the device! I will never buy another TV from Samsung; what an appalling way to alienate your customers!
Ever since I instgalled pi-hole on my network, I'm not seeing ads anymore.
For those not familiar, pi-hole is a network based ad-blocker that runs on a raspberry pi. If you're not into linux you probably don't know about it and it might be a steep learning curve but I guarantee you it will be worth it, for this and ads in general while browsing. Also I think it makes your network much more secure since some malware is attached to ads.
Further to my previous post.
Blocking ads via the TV menu had no effect.
As suggested by others, I then blocked the following on my router security settings
After switching the tv off and back on again the ad in the Smart home ribbon was gone.
As a bonus when I later watched a film via the Rakuten TV app, which was free but required watching three ads, I found the ads only showed a blank screen.
So many thanks for this advice, which is still working the next day! No doubt Samsung will try to work around it but for now I won't be accidentally streaming a Disney movie as happened the other day when I tried to delete the ad!