To fly from the U.K. to Ireland you need a negative PCR Covid-19 test. One woman, a U.K. health care worker, was denied boarding for her flight from Birmingham to Dublin despite having a negative PCR test.
The government doesn’t accept her test, because it was provided by the government – even though it isn’t one of the tests listed as unacceptable. Fortunately there was a workaround to add an enroute stop and avoid the non-sensical requirement.