I did a fresh load of OpenSUSE 15.2 on a 2 Dell 7490 laptops and cloned the 2 to 6 other Dell 7490 (changed the udev 70 rule for different mac addresses) hostname and ip addresses.
Restored the Virtual Machines from the backup done just before the reload. Restored the repos.d directory and used the exact same zypper in to put back all the pieces that are my other apps.
I installed Mate desktop and no other via the install. VirtualBox is Opensuse default - VLC is packman.
VLC and Virtualbox(GUI) take up to 40 seconds on some machines.
All have the same 32GB ram, Disk partitions and 1tb NVME disk.
On some vlc is instant - less than 1 second others 30 seconds - it works fine
On the same ones the vlc is slow VirtualBox Gui takes 30 seconds to appear.
Starting any Virtualbox Machine from a terminal is sub second to appear.
Any Ideas on what might be the cause - is there hardware mac addresses stored somewhere that slow it down vlc and virtualbox - I have looked but see nothing.