If, at any time, a fiduciary becomes insolvent after qualifying as such fiduciary, and after the maturity of a debt owing by such fiduciary to the estate, then the fiduciary and the sureties on the bond shall be liable to the estate for the indebtedness owing by the fiduciary to the estate. If the fiduciary is not solvent at any time after qualification and after the maturity of the debt, the sureties on the bond shall not be liable to the estate for the indebtedness.