autostart fails on host boot. NAT-bridge doesn't come up fast enough

I have 18 VMs that are all supposed to attach to a NAT-bridge. The bridge definition seems to be ok - it used to work when I didn't have any guests defined. It worked when I had only a couple guests defined. Now that I have 18 of them, it seems to take more than a minute for virbr0 to come up, and the guests all fail to autostart because the bridge doesn't exist yet. The host system (AlmaLinux 9.4) has dual Xeon(R) CPU E5-2680v4 with plenty of cores and ram. Is there some easy way to delay the start of the guests to wait for virbr0 to be up? Or can I specify a boot order? I assume that libvirtd autostarts networks before guests but I really have no idea... Can I specify an autostart dependency? As a stopgap measure I turned 'autostart' off on these and made a systemd-run bash script that just starts the network, and then starts the guests all serially. It has worked 10 or so test boots in a row. I'd prefer not to have to use an external script if possible. Fred Clift