tl;dr the command-line solution to run inside your Linux VM:

sudo pkill -fx "/usr/bin/VBoxClient --clipboard" && /usr/bin/VBoxClient --clipboard

Background / Details / Synopsis

Now and again, copy & paste functionality can break between a Microsoft Windows host and its Linux guest VM (Virtual Machine) when using Oracle’s VirtualBox.

Symptoms include not only the inability to paste text, but also application freezes/lockups. For example, we found that Google Chrome on Windows became unresponsive for ~1 minute, when trying to paste text that was copied from our Linux VM, but would return to normal after.

A solution that works for us is to restart the VirtualBox Guest Additions inside the Linux VM, discussed here: How to restart Guest Additions?
https://forums.virtualbox.org/viewtopic.php?f=3&t=99192#p483083