Justin had the news on this on Monday:

This move from the Bank to cut the amount of foreign exchange reserves that financial institutions must hold is a move that is aimed at slowing the yuan's recent devaluation. Yuan has dropped recently to its lowest in 2 years against the rampant USD, which is flexing against pretty much all currencies, not just the yuan. China's currency is not being helped by economic woes from rolling COVID restrictions, power shortages and a collapsing property sector.

The PBOC has been setting firmer-than-expected midpoint guidance rates over the past two weeks. Anoptehr sign the Bank would like to slow the fall of the yuan.

Offshore yuan:

Offshore yuan 06 September 2022