Some more info on the primary investigator fo the "poiscenter-funded POIS study" :
https://psychology.unl.edu/tierney-lorenz The Research interest paragraph shows she has interesting background to investigate the cause of POIS, having studied the link between immunity, hormones, nerouvs system , psychological profile, etc.... and sexual health :
"Dr. Lorenz's research examines the interaction between women's mental, physical and sexual health. The Women, Immunity and Sexual Health (WISH) lab investigates the ways that sexual behavior impact women's immune and endocrine function, as well as ways to help women with mental and/or physical health conditions have happy, healthy sexual lives. We also focus on helping survivors of sexual trauma through basic science and clinical research. Our research draws from evolutionary and feminist science perspectives, and uses methods from multiple fields, including measures of hormones and immune markers, psychophysiological measures of sexual and autonomic arousal, clinical trials, surveys and interviews, and more. "