Hyperpixel 3.5 not working properly on Pi4 about hyperpixel

[Counterdoc]

Feb 25 16:17:06 RPi-IT systemd[1]: hyperpixel-touch.service: Service RestartSec=100ms expired, scheduling restart.
Feb 25 16:17:06 RPi-IT systemd[1]: hyperpixel-touch.service: Scheduled restart job, restart counter is at 5.
-- Subject: Automatic restarting of a unit has been scheduled
-- Defined-By: systemd
-- Support: https://www.debian.org/support

-- Automatic restarting of the unit hyperpixel-touch.service has been scheduled, as the result for
-- the configured Restart= setting for the unit.
Feb 25 16:17:06 RPi-IT systemd[1]: Stopped Hyperpixel LCD Touch Screen Driver Daemon.
-- Subject: A stop job for unit hyperpixel-touch.service has finished
-- Defined-By: systemd
-- Support: https://www.debian.org/support

-- A stop job for unit hyperpixel-touch.service has finished.

-- The job identifier is 273 and the job result is done.
Feb 25 16:17:06 RPi-IT systemd[1]: hyperpixel-touch.service: Start request repeated too quickly.
Feb 25 16:17:06 RPi-IT systemd[1]: hyperpixel-touch.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: https://www.debian.org/support

-- The unit hyperpixel-touch.service has entered the 'failed' state with result 'exit-code'.
Feb 25 16:17:06 RPi-IT systemd[1]: Failed to start Hyperpixel LCD Touch Screen Driver Daemon.
-- Subject: A start job for unit hyperpixel-touch.service has failed
-- Defined-By: systemd
-- Support: https://www.debian.org/support

-- A start job for unit hyperpixel-touch.service has finished with a failure.

[Counterdoc]

Okay it looks like the init service is not starting from time to time. I can start it manually with systemctl and then it is working. I just changed the loglevel of systemd to debug and try to get more detailed information.

[Counterdoc]

I just did two starts of the Pi. No changes done between the starts.
First startup -> display not working
Second startup -> display working

At both times the status of hyperpixel-init says only "loaded", but not active. Journalctl is looking exactly the same at both starts. I don't get it...

Any ideas what else I could check?

[Counterdoc]

I have a workaround for now using a systemd timer that waits 5 seconds after boot to start the hyperpixel-init.service. Looks like there is some kind of timing issue?

[Gadgetoid]

@Counterdoc a timing issue makes sense- although I'm not sure why this should be the case. The Pi 4 is faster, certainly, but I don't think the hyperpixel-init.service depends on anything that wont have started.

Could it, perhaps, be clashing with hyperpixel-touch.service? I believe some pins are shared between the two services, so this could be a race condition.