Lxc-console no prompt Ubuntu 20.04

Hi,
On Ubuntu Server 20.02 LTS, I have sometimes no prompt with lxc-console
$lxc-checkconfig
LXC version 4.0.12
I install my container with the following command :
sudo DOWNLOAD_KEYSERVER="keyserver.ubuntu.com" lxc-create -t download -n test-Rocky -- -d rockylinux -r 9 -a amd64
sudo lxc-start -n 'test-Rocky'

When I make the lxc-console -n "test-Rocky" on one I obtain
Connected to tty 1
Type <Ctrl+a q> to exit the console, <Ctrl+a Ctrl+a> to enter Ctrl+a itself

To avoid the error, of getty service with systemd, I comment the line
ConditionPathExists=/dev/tty0
in the file /var/lib/lxc/test-Rocky/rootfs/etc/systemd/system/getty.target.wants/getty\@tty1.service

but it don’t solve the problem

In debug mode, sudo lxc-start -n "test-Rocky" --logpriority=9 -l DEBUG --logfile=test.log
the line seems to indicate the tty works
lxc-start test-Rocky 20220910124026.211 DEBUG commands - commands.c:lxc_cmd_get_tty_fd_callback:1237 - Send tty to client

We can find the file on https://pastebin.com/nfxmNSKX

I have the same problem with all my container !

The sudo lxc-console -n "test-Rocky" -t 0 works fine but I cannot have many user and I want many users can connect on it, simultaneously

The lxc-attach -n "test-Rocky" -- login works but I have not the issue file print

Have you a solution ?
Thanks

Why not use SSH service or lxc shell $VM?

Because I want to configure the network so ssh is not possible. Moreover, I use LXC and not LXD. So, the lxc shell is not avalaible.