Radio changes volume by itself while moving

If this vehicle is actually “new”, and not just new to you, then it should be covered by multiple warranties from the mfr. That means taking it back to the dealership for free repairs. Let them diagnose it, because if your suggested diagnosis is wrong, then the attempted repairs will not be free.

If this is not really a new vehicle, and is not covered by warranty, then my best guess from afar is a defective clock spring in the hub of the steering wheel.

Edited to add:
For the majority US-based forum members who might be confused about a new MG, I should point out that a Chinese company bought that trademark, and is now manufacturing vehicles in China with that badge. To the best of my knowledge, these vehicles are sold only in Asia and The Middle East.

That took some research. The Philippines MG website says they have a 5 year 100,000 km warranty. The warranty got all of two lines of description. I guess it’s bumper to bumper, and there is no indication of whether the other markets Middle East, South America) have the same warranty. In any case, a 2016 might still be warrantied. MGs owner, SAIC (no, not the American SAIC), is the largest auto manufacturer in China and has the wherewithal to cover problems. The equivalent SUV is sold in China under the brand name Roewe.

The MG owner did not supply the year of manufacture, but you’re correct that it couldn’t be older than the 2016 model year.

We purchased the car in 2020 in UAE. This is the latest 2020 model, and we do have this warranty. The dealership did test drives on our car and other MG cars, all of which have the same issue. We owned a Nissan XTrail bfr this, which did not have this issue, hence the radio signal problem was ruled out, They agreed that this is an issue with their cars. But they dont have a solution for it unfortunately. Hence I was searching around this issue and found this thread here. Thanks for your replies!

One tweet that nobody having this issue has done is go to a large parking lot and drive around in circles. This will tell you if the issue is with the radio or the antenna. Generally you don’t have this problem with whip antenna’s but it is possible.

Window antenna’s are the worse for this as they are generally more directional than whip antenna’s, but a grounding issue with the antenna could cause a whip antenna to become quite directional also.

Electrical problems with an MG! The more things change, the more they stay the same.

Apparently the manufacturer is well aware of the problem. Unfortunately, you will have to wait until they find a fix. This will almost certainly involve replacing the audio unit but you don’t want them to do it with another defective unit.

Yes, but I have to wonder about the type of customer service that will be provided by a manufacturer that is based in a country run by a Totalitarian/Communist regime.
They might not be very responsive to customers’ wants and needs, simply because, in their home country, they don’t have to worry about niceties like that.

That reaction would be a good way to loose customers and eventually shut them out of the market entirely. That’s their problem in the long run of course, but I doubt they are so foolish to tell their first customers to get lost.