Falsus in uno, Falsus in omnibus

Tax-exempt since June 1972 as a 501(c)3 organization. According to its IRS 990 filing; it records $846M in annual revenue. Despite the revenue stream coming from allied non-profits, for-profit companies and its protected status; member stations are always running funding drives while saturating United States education settlements with [sic] “curated content”. Is there any standard for how much time a publicly funded radio station can spend fund raising to broadcast half-truths?