That seems like a minor carbureter adjustment problem. For such a new bike it’s obviously under waranty so just take it back to the dealer.
Associating 91 octane with the word “premium” is false advertising, a big marketing lie to charge ill informed consumers more money. There are bikes/cars that are designed to run on 91 octane, but for the majority of bikes/cars that are designed to run on 87 octane, paying higher price for 91 octane is like paying for and taking medecine that you don’t need. Check your owner’s manual for your bike/car’s octane requirement.