There was a video that mentioned that it was due to 2 reasons. Unbalanced rims and tyres with poor quality. The chap who did the video on it mentioned that he had 1st did rim balancing and then changed to better tyres...seems to have solved the problem.

Yummy gold USD forks. But what's with the random rainbow?

I managed to take the bike for a short test ride around Gasket. Here is my review:

I rode a bike and I liked it...actually, I liked it a lot! It's not super powerful and you might be maxing out every gear but in the city, it's capital FUN! By the way, even my old Panther was much faster. But no, it's not a highway warrior type bike but more of a B road santai ride. And, it will do well in that environment. You're encouraged to look around more, less bothered about the speed instead, enjoy the experience. Brakes felt good but maybe it's because of the lighter weight and also the lower speed. And the tyres did well in the wet too. Anyway, I'm not a proper reviewer, go try it for yourself. But this bike gave me grins the whole test ride. It's the New Royal Enfield Hunter 350.

Here's a video of a test ride done by Bennetts of UK
https://www.youtube.com/watch?v=tqSizY37mQI