A Wi-Fi multi-link device, in the following also referred to as MLD, comprising: a transmit, in the following also referred to as TX, circuit; a receive, in the following also referred to as RX, circuit; and a control circuit, arranged to control the RX circuit to receive a first frame under an operation mode parameter with a first setting, control the TX circuit to transmit a second frame responsive to the first frame under the operation mode parameter with the first setting, and after the second frame is transmitted, control the RX circuit to receive at least one physical layer protocol data unit, in the following also referred to as PPDU, under the operation mode parameter with a second setting, wherein the second setting is different from the first setting; characterized in that before the first frame is received, the control circuit is further arranged to control the RX circuit to receive a third frame under the operation mode parameter with the first setting, and control the TX circuit to transmit a fourth frame responsive to the third frame under the operation mode parameter with the first setting; the first frame is an inquiry frame, and the second frame is a response frame that is responsive to the inquiry frame and carries indication of operation mode parameter change that specifies the use of the second setting; the third frame is one of a request to send, in the following also referred to as RTS, frame, a multi-user request to send, in the following also referred to as MU-RTS, frame and a buffer status report poll, in the following also referred to as BSRP, frame; and the fourth frame is one of a clear to send, in the following also referred to as CTS, frame and a buffer status report, in the following also referred to as BSR, frame; and the operation mode parameter is a number of spatial streams, a bandwidth, a decoding capability, a maximum media access control protocol data unit, in the following also referred to as MPDU, length, a maximum aggregate media access control service data unit, in the following also referred to as A-MSDU, length, or a maximum aggregate media access control protocol data unit, in the following also referred to as A-MPDU, length exponent. a transmit, in the following also referred to as TX, circuit; a receive, in the following also referred to as RX, circuit; and a control circuit, arranged to control the RX circuit to receive a first frame under an operation mode parameter with a first setting, control the TX circuit to transmit a second frame responsive to the first frame under the operation mode parameter with the first setting, and after the second frame is transmitted, control the RX circuit to receive at least one physical layer protocol data unit, in the following also referred to as PPDU, under the operation mode parameter with a second setting, wherein the second setting is different from the first setting; characterized in that before the first frame is received, the control circuit is further arranged to control the RX circuit to receive a third frame under the operation mode parameter with the first setting, and control the TX circuit to transmit a fourth frame responsive to the third frame under the operation mode parameter with the first setting; the first frame is an inquiry frame, and the second frame is a response frame that is responsive to the inquiry frame and carries indication of operation mode parameter change that specifies the use of the second setting; the third frame is one of a request to send, in the following also referred to as RTS, frame, a multi-user request to send, in the following also referred to as MU-RTS, frame and a buffer status report poll, in the following also referred to as BSRP, frame; and the fourth frame is one of a clear to send, in the following also referred to as CTS, frame and a buffer status report, in the following also referred to as BSR, frame; and the operation mode parameter is a number of spatial streams, a bandwidth, a decoding capability, a maximum media access control protocol data unit, in the following also referred to as MPDU, length, a maximum aggregate media access control service data unit, in the following also referred to as A-MSDU, length, or a maximum aggregate media access control protocol data unit, in the following also referred to as A-MPDU, length exponent.