Could we also take the model code of your Soundbar please? You can find this on a label at the back of the Soundbar.
Oh dear! It does sound as though it would need to be inspected by one of our engineers. Have a look at the following link, to see your repair options: https://www.samsung.com/uk/support/repair/
We appreciate you keeping us updated, @Danno72. Please let us know when you get your subwoofer working as expected again. 👍