This preprint (not yet peer reviewed) study concludes that 90 days post Omicron infection in a highly vaccinated population (94%) of over 11K people in Australia, almost 1 in 5 respondents (18.2%)  reported #LongCovid  symptoms (median 6 symptoms).
https://www.medrxiv.org/content/10.1101/2023.08.06.23293706v1