Arch Linux guest (Virtualbox): vboxdrv.service fails at startup

I am running Windows 10 as a Virtualbox Host and Arch Linux as Guest. During startup, vboxdrv.service fails. The tty starts fine, I can do everything inside it. However, startx leads to what I believe to be the normal stdout, but after that, nothing happens, I have no graphical interface, my i3wm does not start. My guess is that this behaviour is linked to vboxdrv.service failing at startup. Relevant information might be: systemctl status vboxdrv.service:

vboxdrv.service - VirtualBox Linux kernel module
     Loaded: loaded (/opt/VirtualBox/vboxdrv.sh; enabled; vendor preset: disabled)
     Active: failed (Result: exit-code) since Sun 2020-04-05 11:25:10 CEST, 11 min ago
    Process: 359 ExecStart=/opt/VirtualBox/vboxdrv.sh start (code=exited, status=1/FAILURE)

Apr 05 11:25:08 archlinux-vm systemd: Starting VirtualBox Linux kernel module...
Apr 05 11:25:10 archlinux-vm vboxdrv.sh: vboxdrv.sh: Starting VirtualBox services.
Apr 05 11:25:10 archlinux-vm vboxdrv.sh: Starting VirtualBox services.
Apr 05 11:25:10 archlinux-vm vboxdrv.sh: vboxdrv.sh: failed: modprobe vboxpci failed. Please use 'dmesg' to find out why.
Apr 05 11:25:10 archlinux-vm systemd: vboxdrv.service: Control process exited, code=exited, status=1/FAILURE
Apr 05 11:25:10 archlinux-vm systemd: vboxdrv.service: Failed with result 'exit-code'
Apr 05 11:25:10 archlinux-vm systemd: Failed to start VirtualBox Linux kernel module.

dmesg | grep vboxpci yields nothing. dmesg | grep vboxdrv:

[    7.200636] vboxdrv: loading out-of-tree module taints kernel.
[    7.200840] vboxdrv: module verification failed: signature and/or required key missing - taintig kernel
[    7.209208] vboxcrv: Found 1 processor cores
[    7.246471] vboxdrv: TSC mode is Invariant, tentative frequency 2711995959 Hz
[    7.246472] vboxdrv: Successfully loaded version 6.1.4 (interface 0x002d0001)

startx:

X.Org X Server 1.20.8
X Protocol Version 11, Revision 0
Build Operating System: Linux Arch Linux
Current Operating System: Linux archlinux-vm 5.5.13-arch2-1 # SMP PREEMPT Mon, 30 Mar 2020 20:42:41 +0000 x86_64
Kernel command line: BOOT_IMAGE=/boot/vmlinuz-linux root=UUID=894e6e02-38f6-4798-b936-431c8287803a rw quiet
Build Date: 30 March 2020 05:05:45AM

Current version of pixman: 0.38.4
        Before reporting problems, check http://wiki.x.org 
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational, 
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/home/[username]/.local/share/xorg/Xorg.0.log", Time: Sun Apr  5 11:25:30 2020
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
_

and blocking the tty. pacman -Qs virtualbox:

local/virtualbox-guest-modules-arch 6.1.4-12
    Virtualbox guest kernel modules for Arch Kernel
local/virtualbox-guest-utils 6.1.4-5
    VirtualBox Guest userspace utilities
local/virtualbox-host-modules-arch 6.1.4-12
    Virtualbox host kernel modules for Arch Kernel

EDIT: I have updated the machine again (it asked me whether I want to replace virtualbox-guest-modules with linux, I gladly agreed in hope of fixing the problem with the update, but behaviour stays the same), new pacman -Qs virtualbox:

local/linux 5.6.2.arch1-2
    The Linux kernel and modules
local/virtualbox-guest-utils 6.1.4-5
    VirtualBox Guest userspace utilities
local/virtualbox-host-modules-arch 6.1.4-15
    Virtualbox host kernel modules for Arch Kernel

This has been happening for about two weeks now, probably after updating my machine. Before, everything was fine. What can I do?