Researchers from RMIT in Australia have found that feelings of loneliness or isolation can hinder an astronaut’s ability to smell and taste, despite having carefully designed meal plans. This is due to bodily fluids shifting to the upper part of the body in microgravity, causing facial swelling and nasal congestion.
Source: https://www.wionews.com/web-stories/science/why-do-astronauts-lose-their-sense-of-taste-in-space-1731174737800