Virtual box broken after kernel update to 5.8

Hi, I got a problem in oracle Virtual box after update the kernel version from 5.4.0-XX to version 5.8.XXX on Focal Fossa. After system restart it can not load Windows virtual machine. Warning is: virtualbox-dkms doesn not have kernel module sources and has to be reinstalled. So after reinstall Virtual box is not working again. Tried some configuration without any success. Only good thing was that I have backup and after installing Ubuntu 18.04 virtual machine is now working again on a kernel 5.4.0-60. Does someone else got similar problem and where could be the problem? My hardware is i5-2430M CPU @ 2.40GHz × 4 , HD Graphics 3000, 8GB RAM, SSD 500. Something else: Kernel 5.8 delayed the system performance almost two times during the boot.