From the transcript

However, many tribes said the federal funds they received did not fully meet their needs. Tribes we spoke with said federal housing support was generally helpful, but they also cited its limitations. Program restrictions, such as income limits, affected tribes' ability to support housing needs of middle-income households. The inability of federal funds to keep pace with construction, rehabilitation, or maintenance costs was another major concern. And just the low availability of housing in tribal areas limited tribes' use of some programs, such as certain homeownership programs.