HUD's 2018 Annual Homeless Assessment Report (AHAR) to Congress is based on a single night in January 2018, because people enter and leave homelessness, so talking about a fixed population is difficult.
On that night, 48.9% of all the 552,830 people counted as homeless were white. But 72% of the population, according to HUD, is white (although as they don't break out non-Hispanic white as the Census Bureau does, the 72% may be overstated). So, whites are underrepresented among the homeless. That shouldn't be a surprise. They're also underrepresented among the poor, although they form the largest group of impoverished people.
Forbes
https://www.forbes.com/sites/eriksherman/2018/12/29/homelessness-has-racial-gender-and-age-disparities/?sh=5719dce93c36