Thank you for your quick reply.
Based on your information, I found that this is most likely a high-side switch IC for USB power line.
I couldn't find the corresponding product in the S11 marking, but I thought so because the signal from the rocker switch reaches the pins of this IC.
However, the strange thing is that the differential signal from USB TypeC is connected to this IC.
The ferrite next to the IC seems to be a CMCC inserted in the USB differential signal line connecting the USB TypeC receptacle and the XMOS MCU.
Fortunately, I confirmed that the MOTU M4 works by shorting the two pins on the MCU side of the pattern of this IC. (The rocker switch does not work. but it starts immediately when the USB cable is connected.)
This is the operation to input 5V from USB to the DCDC converter power supply of the MCU.
My M4 has no audio output because the TPS65133, which generates the +-5V power supply for the internal op-amps, is burned out and I plan to replace it.
I will solder the new chip when it arrives.
The short circuit made the M4 work, but I'm still collecting information about the 6-pin IC marked S11, because I'm worried about the possibility of unexpected behavior.
Thank you guys !!