Unable to Get Drag & Drop to Work on Xubuntu 20.04 with VirtualBox 6.1.30

It's all in the title. I've tried installing from the guest additions CD by running the .run file on there. Though, most of the time, Xubuntu seems to be utterly incapable of mounting the CD in such a way that it shows it as anything other than an empty volume.

I've also tried all these commands:

sudo apt-get install build-essential linux-headers-generic
sudo apt install gcc
sudo apt-get install build-essential gcc make perl dkms
sudo apt-get install virtualbox-guest-utils

The shared clipboard continues to work, but Xubuntu seems to be completely incapable of handling something as basic as drag & drop for some reason. Any help you guys can offer for this absurd issue would be greatly appreciated.

The output from ls /opt:

VBoxGuestAdditions-6.1.30

The output from dpkg -l | grep virtualbox:

ii  virtualbox-guest-utils                6.1.26-dfsg-3~ubuntu1.20.04.2         amd64        x86 virtualization solution - non-X11 guest utilities

You have to uninstall binary VBoxGuestAdditions by

sudo /opt/VBoxGuestAdditions-6.1.30/uninstall.sh

and then install one additional deb-package using command below

sudo apt-get update
sudo apt-get install virtualbox-guest-x11

and reboot VM.

^{KlingL here: As it turns out, the issue was VirtualBox drag and drop not supporting Xubuntu's Thunar file manager. I could still drag and drop files to the desktop.}

^{I marked this answer as correct to thank N0rbert for taking the time to try to help me fix this issue. Another imporant thing N0rbert mentioned in the comments is how trying to use an enviornment as lightweight as XUbuntu comes with consequences such as the issue around which this whole question is based.}