OK yeah this is a regression. It may depend on some CPU and kernel interaction to set up the entropy pool, so the problem could appear on some systems and not on others. I'm not seeing this in a VM, but on baremetal.
If I downgrade to systemd-242-6.git9d34e79.fc31 the problem goes away.
I started a thread upstream. https://lists.freedesktop.org/archives/systemd-devel/2019-August/043231.html