If you have a UPS attached to your machine with USB, that can cause Windows 10 to assume you are on a portable device and thus require Flight Mode.
This was the case for me and I was unable to turn Flight Mode off. My machine was upgraded from Windows 7 and since, I have spurious connection issues causing huge lock ups on the machine. I am hoping my resolving the Flight Mode issue resolves the network issues.
Consider it's related to power save settings on Wired or wireless network adapter. Please try to check on this option:

If this doesn't work, export the energy report by running this commands and post here:
powercfg /energy
I have noticed this error in your energy report, it seems that there is the USB mouse may cause your issue. Please unplug this mouse and see if your sleep can work fine.
USB Suspend:USB Device not Entering Selective Suspend
This device did not enter the USB Selective Suspend state. Processor power management may be prevented when this USB device is not in the Selective Suspend state. Note that this issue will not prevent the system from sleeping.
Device Name USB Composite Device
Host Controller ID PCI\VEN_8086&DEV_9D2F
Host Controller Location PCI bus 0, device 20, function 0
Device ID USB\VID_046D&PID_C52F (This is an usb mouse device)
Port Path 2
See these: please configure your sleep mode again, in advanced power option, enable USB settings:

Power Policy:Sleep timeout is disabled (Plugged In)
The computer is not configured to automatically sleep after a period of inactivity.
Power Policy:USB Selective Suspend is disabled (Plugged In)
The current power policy has globally disabled USB selective suspend.
Weird issue.
Not sure if this is related to the insider preview version. Since such version of Windows are still in testing, some issue can be noticed when it was used, you can submit some feedback to see if there's any similar issue.
At this time, i would like to suggest you to update the BIOS and run commands below to repair system components:
Dism /Online /Cleanup-Image /RestoreHealth
SFC /scannow
Best Answer
Airplane mode is enabled automatically, how do I turn it off?
Source How to Turn On or Off Airplane Mode in Windows 10