Complexities in the state of California, likely the same in other states.
One media outlet did a deep dive on warning systems in California, see Emergency warning systems present patchwork of problems.
These are well-known problems that can only be fixed by states taking action legislatively. I suppose that in some states with "home rule," that also might complicate the effort. Failing a state-dictated solution, there could be an effort to standardize much of the warning systems just by convening emergency managers and seeking compromises where possible. This would of course require work by those responsible.
Claire Rubin shared the link above.