  We report an inelastic neutron scattering study of single crystals of
(Li$_{0.8}$Fe$_{0.2}$)ODFeSe. Temperature-dependent low-energy spin excitations
are observed near $\mathbf{Q}=$ (0.5, 0.27, 0.5) and equivalent wave vectors
symmetrically surrounding $\mathbf{Q}=$ (0.5, 0.5, 0.5) in the 1-Fe Brillouin
zone, consistent with a Fermi-surface-nesting description. The excitations are
broadly distributed in energy, ranging from 16 to 35 meV. Upon cooling below
the superconducting critical temperature ($T_\mathrm{c}$), magnetic response
below twice the superconducting gap $2\Delta_\mathrm{SC}$ exhibits an abrupt
enhancement, consistent with the notion of spin resonance, whereas the response
at higher energies increases more gradually with only a weak anomaly at
$T_\mathrm{c}$. Our results suggest that (Li$_{0.8}$Fe$_{0.2}$)ODFeSe might be
on the verge of a crossover between different Cooper-pairing channels with
distinct symmetries.
