Qvm-open-in-dvm not working (for URLs)

qvm-open-in-dvm is not working for me in 4.0.4. From a source VM running fedora-33, I run and get the following output:

$ qvm-open-in-dvm https://qubes-os.org

(firefox:952): Gdk-CRITICAL **: 10:17:35.736: gdk_atom_intern: assertion 'atom_name != NULL' failed
$

Qubes starts a disposable VM, but without opening anything, within 10 seconds the newly started disposable VM is halted:

Domain disp5635 is starting
Domain disp5635 has started
Domain disp5635 has halted

/etc/qubes-rpc/policy/qubes.OpenInVM looks like the following:

$anyvm $dispvm allow
$anyvm $anyvm ask

journalctl logs in dom0:

[user@dom0 ~]$ journalctl | grep disp5635
Jun 17 10:23:20 dom0 qubesd[1799]: Creating directory: /var/lib/qubes/appvms/disp5635
Jun 17 10:23:20 dom0 qubesd[1799]: Creating icon symlink: /var/lib/qubes/appvms/disp5635/icon.png -> /usr/share/icons/hicolor/128x128/devices/appvm-red.png
Jun 17 10:23:21 dom0 qubesd[1799]: Starting disp5635
Jun 17 10:23:23 dom0 qubesd[1799]: Activating the disp5635 VM
Jun 17 10:23:32 dom0 qrexec[30630]: qubes.WindowIconUpdater: disp5635 -> dom0: allowed to dom0
Jun 17 10:23:35 dom0 qubesd[1799]: permission denied for call b'admin.vm.property.Get'+b'qid' (b'dom0' → b'disp5635') with payload of 0 bytes
Jun 17 10:23:35 dom0 qubesd[1799]: permission denied for call b'admin.vm.device.block.Available'+b'' (b'dom0' → b'disp5635') with payload of 0 bytes
Jun 17 10:23:35 dom0 qubesd[1799]: permission denied for call b'admin.vm.List'+b'' (b'dom0' → b'disp5635') with payload of 0 bytes
Jun 17 10:23:35 dom0 qubesd[1799]: permission denied for call b'admin.vm.volume.Info'+b'volatile' (b'dom0' → b'disp5635') with payload of 0 bytes
Jun 17 10:23:36 dom0 qubesd[1799]: Removing volume private: qubes_dom0/vm-disp5635-private
Jun 17 10:23:36 dom0 qubesd[1799]: Removing volume root: qubes_dom0/vm-disp5635-root
Jun 17 10:23:36 dom0 qubesd[1799]: Removing volume volatile: qubes_dom0/vm-disp5635-volatile
Jun 17 10:23:42 dom0 qrexec[30630]: qubes.WindowIconUpdater: disp5635 -> dom0: denied: qrexec-client failed
[user@dom0 ~]$ 

Console output for the disposable VM seems okay:

[user@dom0 ~]$ tail /var/log/xen/console/guest-disp5635.log 
[.[0;32m  OK  .[0m] Started .[0;1;39mUser Manager for UID 1000.[0m.
[.[0;32m  OK  .[0m] Started .[0;1;39mSession c1 of user user.[0m.
[.[0;32m  OK  .[0m] Started .[0;1;39mSession c2 of user user.[0m.
[.[0;32m  OK  .[0m] Started .[0;1;39mSession c3 of user user.[0m.
[    7.553524] fbcon: Taking over console

Fedora 33 (Thirty Three)
Kernel 5.4.120-1.fc25.qubes.x86_64 on an x86_64 (hvc0)

disp5635 login: 

Are there other logs I should be looking at to determine what the issue is?

Might be related to Whonix DispVM Fails with "Got empty response from qubesd" "KeyError" unhandled exception while calling src=b'dom0' meth=b'admin.vm.List' · Issue #5121 · QubesOS/qubes-issues · GitHub

Edit: not this.

This is the issue: Dispvm automatically killed just after being created. qvm-open-in-vm / OpenURL · Issue #6562 · QubesOS/qubes-issues · GitHub