Good. Thanks for testing it out

Explanation (quoted from pullrequest)

If the udev rule gets triggered during device startup (i.e.
when device is booted up while toh is attached), a circular
startup dependency occurs: udev-settle does not finish until
tohkbd2 is started - and booting up to the state where tohkbd2
could be started is waiting for udev-settle to finish. While
the circular dependency gets broken eventually, it happens via
units timing out / failing and causes issues here and there.

As a workaround use asynchronous start/stop operations from
udev rules so that tohkbd2 startup gets queued, but is not
required to finish before continuing with other things.

But i don't know what change triggered this, but i suspect that it is something in systemd, or in service startup order dependencies. iirc systemd was updated at those times.