The title is misleading - the productivity drop in Q1 2022 is almost equal to the increase in Q4 2021. Together, they average out. This is visible on the first graph, where two roughly equal bars go up and down on the right hand (near-present) side.
Overall productivity seems to be up since 2020, according to the hours worked / output series in chart 3. Output had already recovered to pre-pandemic levels in Q3 2021, but hours worked did not - leading to an improved productivity ratio as the BLS calculates it.