(Liberal) nationalism and individualism are not necessarily incompatible, especially if we start from a naturalistic understanding of political philosophy.
The desire for membership in a society is natural, and it is from this desire that nation-state emerged (Anhart 2024a).:
But I do recognize that there is a natural desire for membership in a society, which arose in the evolutionary state of nature of our hunter-gatherer ancestors, and that this natural desire for social membership can be satisfied in a multiethnic Lockean liberal nation like the United States.
The earliest classical liberals recognized that individuals, although caring for themselves (individualism) also care for greater entities like family and nation (Adam Smith, The Theory of Moral Sentiments):
The administration of the great system of the universe, however, the care of the universal happiness of all rational and sensible beings, is the business of God and not of man. To man is allotted a much humbler department, but one more suitable to the weakness of his powers, and the narrowness of his comprehension: the care of his own happiness, of that of his family, his friends, his country. That he is occupied in contemplating the sublime can never be an excuse for neglecting the more humble department. . . . The most sublime speculation of the contemplative philosopher can scarce compensate the neglect of the smallest active duty.17
That doesn't encompass from being a strong individualist (Anhart 2022):
The new Darwinian social science supports the fundamental idea running through all of Smith's writing--the evolution of unintended order--and in doing that, it supports Smithian liberalism, or what Smith calls "the system of natural liberty," which allows "every man to pursue his own interest his own way, upon the liberal plan of equality, liberty, and justice" (WN, 664, 687).
Taking "individualism" too far, neglecting individuals social nature (needs for social ties like friendship, romantic love, family, society), is irrealistic, and therefore could not make a basis for a good classical liberal political philosophy.
The point is to "make society" around values which protect individual liberty and dignity, and respect the classical liberal "harm principle" with regard to other societies (Anhart 2024b).