[pps43]

The tests themselves are fine, false positives are due to human error:

"The high specificities (usually 100%) reported in PCR-based tests for SARS-CoV-2 infection do not represent the real-world use of these tests, where contamination and human error produce significant rates of false positives."

New York reports positivity rate below 1% for a while now, so false positive rate cannot be 2.3%.

[cameldrv]

If the false positive mechanism is contaminating one sample with another, the false positive rate will depend on the true positive rate in the samples that the lab/testing site is processing. The other possibility would be if positive control amplicon contaminated the lab, which does happen.

[pps43]

The underlying assumption behind false positive rate is that tests are independent and identically distributed. If in practice this is not the case, then false positive rate becomes misleading.