That’s been a long-standing problem. So has the lack of consequences for those responsible; in general, agencies have discretion over whether, and how, to discipline employees.
President Trump last week signed into law a bill requiring that agencies take disciplinary action against officials who are found — by the agency head or inspector general, or in legal proceedings — to have taken retaliatory personnel actions. For a first offense, that would range from a three-day suspension up to firing. Firing would be required on a second offense. Those officials would have regular appeal rights, though.
Similar policies have applied since last year at the Department of Veterans Affairs, where a surge of retaliation complaints followed whistleblower disclosures. Mandatory firing also applies to some types of misconduct at the Internal Revenue Service. History shows that such authorities are rarely used, but they do send a message.