“False-positive results appear to be common. According to a 2017 report , 22 percent of 479 subjects received a false-positive anti-HCV test. According to a 2020 report, the rate of false-positive test results among 1,814 reactive serum samples was 10 percent.”
https://www.healthline.com/health/hepatitis-c-false-positive#how-common-is-it
“ Causes of a false-positive hepatitis C test
You may receive a false-positive result if your antibodies are triggered by another infection. People who've recovered from hepatitis C on their own may also get a false-positive anti-HCV test result. In rare cases, lab error leads to a false positive.”
https://www.healthline.com/health/hepatitis-c-false-positive