Have tried various versions of Openwrt on Virtualbox 6.0.4, including 18.06.x and 17.01.x. Everytime the VM becomes extremely slow during the boot process.
I then downgrade to Virtualbox 5.2, because I have another setup running fine for similar setup. Everything goes well with version 5.2. Any one has a clue?
The host machine is an old DELL R320.