Topological protection for topological systems may change by the inclusion of particle-particle interaction, which is known as “reduction phenomena.” Here we have pointed out its possibilities for 1-dimensional non-Hermitian systems with point gap topology.
Have a look at “Reduction of one-dimensional non-Hermitian point-gap topology by interactions” by Tsuneya Yoshida and Yasuhiro Hatsugai, which has been published in Physical Review B (Nov.28, 2022). See also arXiv:2205.09333.