VirtualBox Manager UI elements flicker with compositing disabled

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Since upgrading to 6.1.30, the manager UI (not the guest window) seems to flicker/lag when interacting with certain UI elements. Enabling compositing in xfwm4 fixes the issue.

System details:

user@host:~$ vboxmanage --version
6.1.30r148432
user@host:~$ cat /etc/*release
PRETTY_NAME="Debian GNU/Linux bookworm/sid"
NAME="Debian GNU/Linux"
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"
user@host:~$ uname -a
Linux host 5.14.0-2-amd64 #1 SMP Debian 5.14.9-2 (2021-10-03) x86_64 GNU/Linux
user@host:~$ lspci -k | grep -A3 VGA
00:02.0 VGA compatible controller: Intel Corporation CometLake-U GT2 [UHD Graphics] (rev 02)
	Subsystem: Lenovo UHD Graphics
	Kernel driver in use: i915
	Kernel modules: i915
user@host:~$ xfwm4 --version
	This is xfwm4 version 4.16.1 (revision 5f61a84ad) for Xfce 4.16
	Released under the terms of the GNU General Public License.
	Compiled against GTK+-3.24.24, using GTK+-3.24.30.

	Build configuration and supported features:
	- Startup notification support:                 Yes
	- XSync support:                                Yes
	- Render support:                               Yes
	- Xrandr support:                               Yes
	- Xpresent support:                             Yes
	- X Input 2 support:                            No
	- Embedded compositor:                          Yes
	- Epoxy support:                                Yes
	- KDE systray proxy (deprecated):               No
user@host:~$ xfconf-query -c xfwm4 -p /general/use_compositing
false
user@host:~$ sudo X -version
[sudo] password for user: 

X.Org X Server 1.20.11
X Protocol Version 11, Revision 0
Build Operating System: linux Debian
Current Operating System: Linux host 5.14.0-2-amd64 #1 SMP Debian 5.14.9-2 (2021-10-03) x86_64
Kernel command line: BOOT_IMAGE=/vmlinuz-5.14.0-2-amd64 root=/dev/mapper/host--vg-root ro quiet
Build Date: 13 April 2021  04:07:31PM
xorg-server 2:1.20.11-1 (https://www.debian.org/support) 
Current version of pixman: 0.40.0
	Before reporting problems, check http://wiki.x.org
	to make sure that you have the latest version.
user@host:~$ 

Video of issue attached. (Apologies for phone camera video. Recording the window with ffmpeg -f x11grab ... makes the issue disappear.)

Same issue on latest v6.1.31 test build.