Opting out of staking on a crypto exchange

Hi, I use SBI VC Trade exchange in Japan.

The default setting is to receive rewards for Ether staking.

I can turn this off, but the exchange won't confirm whether this actually stops my Ether from being staked or whether they carry on regardless.

I have tried contacted support countless times but they cannot/will not answer straight.

What is the usual practice when it comes to opting in and out of Ether staking on exchanges?

How high is the risk of slashing. SBI is a major online brokerage platform in Japan…