I recently answered a similar question here u/enygma9753 about the precarious situation Quebec found itself in at the outbreak of the Revolution.

Quebec (also known as Canada or "the Canadas" at the time) was a colony under British rule since 1763, separate from the Thirteen Colonies. It had no assembly and was ruled by an appointed Governor and Executive Council. This, and the generous accommodations under the Quebec Act for French Catholics, outraged the American colonists who cited these grievances as intolerable.

After the Seven Years War, France willingly gave up Quebec to Britain in 1763 during peace negotiations in exchange for Guadaloupe, which was an immensely profitable sugar colony. The habitants of Quebec resented that France had cast them aside to an uncertain fate under British rule. Some even regarded it as a betrayal.

Britain, fearing the risk of open revolt in Canada as tensions simmered in the Thirteen Colonies, made great efforts to win over the loyalty of the French Canadians. They partially succeeded -- Quebec would not get involved in the Revolution, but they wouldn't take up arms for Britain either.

The link above explains why Quebec saw any active involvement in the American Revolution on either side as a no-win situation.

The Americans' heavy-handed occupation of Montreal and the doomed attack on Quebec City in 1775 also didn't help their cause.