I used USBlyzer
The keyboard shows up as 3 devices but the one that reported the sleep scancode was called "HID-compliant consumer control device".
I tried to attach the CSV file but it says I'm not permitted. Here's the CSV data from USBlyzer (I'm not sure it this is what you need)"
I pressed the sleep button twice. Seq 0002-0003 is for the first time I pressed it and 0004-0007 is for the second time I pressed it.
-----
USBlyzer Report Capture List Type,Seq,Time,Elapsed,Duration,Request,Request Details,Raw Data,I/O,C:I:E,Device Object,Device Name,Driver Name,IRP,Status START,0001,8:28:40.209,,,,,,,,,,,, URB,0002,8:28:41.910,1.687732 s,,Bulk or Interrupt Transfer,3 bytes buffer,,in,01:01:82,FFFFFA801A7121B0h,00000104,usbccgp,FFFFFA801A6F4A80h, URB,0003,8:28:42.268,2.055734 s,,Bulk or Interrupt Transfer,3 bytes buffer,,in,01:01:82,FFFFFA801A7121B0h,00000104,usbccgp,FFFFFA801A5D4BD0h, URB,0004-0002,8:28:47.053,6.840020 s,5.152288 s,Bulk or Interrupt Transfer,Input Report id:2 len:2,02 02,in,01:01:82,FFFFFA801A7121B0h,00000104,usbccgp,FFFFFA801A6F4A80h,Success (Success),02 02 URB,0005,8:28:47.053,6.840039 s,,Bulk or Interrupt Transfer,3 bytes buffer,,in,01:01:82,FFFFFA801A7121B0h,00000104,usbccgp,FFFFFA801A6F4A80h, URB,0006-0003,8:28:47.193,6.984012 s,4.928278 s,Bulk or Interrupt Transfer,Input Report id:2 len:2,02 00,in,01:01:82,FFFFFA801A7121B0h,00000104,usbccgp,FFFFFA801A5D4BD0h,Success (Success),02 00 URB,0007,8:28:47.193,6.984018 s,,Bulk or Interrupt Transfer,3 bytes buffer,,in,01:01:82,FFFFFA801A7121B0h,00000104,usbccgp,FFFFFA801A5D4BD0h, This report was generated by USBlyzer http://www.usblyzer.com/ ------
If you need the .ulz file, please let me know and I'll send it to you.
Thanks again for your help.