This may be leaning into ASB but i thought i would post and see how it went.
What if during the American Revolutionary War, instead of the monarchy being unfairly demonised by the revolutionaries, the blame was properly put on Parliament throughout the revolution with a majority of the coloniest seeing the monarch in a neutral or postive light.
The monarchs power in the colonies can be large or minimal depending on which you think is the most likely but Parliament can have no say.in the running of the.colonoes.
No specific way of achieving this that i can think of so let's hear your idea's.