SUSE Linux 15 - ifcfg-eth0 deleted after reboot

I have a Virtual Machine with a clean installation of SUSE Linux For SAP Applications 15. I configured the network with YaST Network (IP address assigned, file /etc/sysconfig/network/ifcfg-eth0 automatically created, everything looked good). When OS is rebooted, file ifcfg-eth0 is missing and I have to configure the network again. Does anybody know why file ifcfg-eth0 is deleted after reboot? Does OS do it on purpose? Do I need SUSE License?