Profile setup in driver E.G. undervolting etc., after every reboot back to default Bug found.
After months of searching, the culprit was the "Gigabyte Performance Libary addon" from the Gigabyte Control Center Util.
Uninstalled GBT Performance Libary and now the settings in the AMD Adrenalin driver are retained after a restart.
Info for others have the same problem, although fastboot off and Windows KB uninstalled.
greetz