You are absolutely right, alcohol affects people of various racial groups and ethnicities differently.
When one researches such differences, a notable example of this is seen in Asian populations, a phenomena coined the "red flush" where the complexion of Asian people appears more red while drinking. This claim in itself was tested by A. W. Chen for PubMed, with promising results. Out of the participants tested, 47-85% of Asian participants experienced red flush while only 3-29% of white participants did. This is an interesting point, but lacks testing or at least results from other ethnic groups, notably those of Black participants.
In a subsequent study by Sarah L. Pedersen, Ph.D. and Denis M. McCarthy, Ph.D. for PubMed as well, they more closely studied effects on Black and white participants. Out of the 178 participants, 57% of which were Black, they concluded that Black participants specifically showed stronger responses to alcohol than white participants. Their research concluded that "African Americans experienced sharper increases in stimulation on the ascending limb compared to European Americans. African American women experienced sharper increases in sedation on the ascending limb compared to European American women. Change in sedation on the ascending limb was associated with past month drinking behavior. Stimulation on the ascending limb was related to alcohol-problems for African Americans but not European Americans."
I hope this answered your question and helped strengthened your correct hypothesis.
A. W. Chen "Racial differences in alcohol sensitivity"
https://pubmed.ncbi.nlm.nih.gov/2937417/
Sarah L. Pedersen, Ph.D. and Denis M. McCarthy, Ph.D. "Differences in Acute Response to Alcohol between African Americans and European Americans"
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3664260/