Id download and run Malwarebytes first, free 7 day trial, scan and quarantine any issues. Are you changing resolution settings at all or switching between two monitors ?
Are the placement of icons being placed at random at each reboot? Or are they scattered always in the same spot at each reboot regardless of how you re-arrange them again?
If it's the former, it could be malware related. If it's the latter, most likely a Windows problem not saving your preferences and then reverting back to the previous state after a reboot. You can try rebuilding the IconCache file in the link below.