Clipboard changes?

[MR ZenWiz]

Did anything change in any recent updates with the way the system
clipboard is handled?

I ask because the clipboard works fine on my Xubuntu 18.04 host, but
the bidirectional clipboard setup between the host and my VirtualBox
VMs no longer works.

I suspect this is a VB issue because at work I run Win 10 with an
Xubuntu VM and it fails there, too.  (At home I run Xubuntu with Win 7
VMs.)

Thanks.

Mark