Crash after boot

[genodeftest]

When enabling Freifunk AutoConnect to start at boot on my Android 9 smartphone, it crashes at every reboot.

--------- beginning of crash
5465 E AndroidRuntime: FATAL EXCEPTION: main
5465 E AndroidRuntime: Process: com.example.tobiastrumm.freifunkautoconnect, PID: 5465
5465 E AndroidRuntime: java.lang.RuntimeException: Unable to start receiver com.example.tobiastrumm.freifunkautoconnect.BootCompletedReceiver: java.lang.IllegalStateException: Not allowed to start service Intent { cmp=com.example.tobiastrumm.freifunkautoconnect/.NotificationService (has extras) }: app is in background uid UidRecord{52b1103 u0a210 RCVR idle change:uncached procs:1 seq(0,0,0)}
5465 E AndroidRuntime: 	at android.app.ActivityThread.handleReceiver(ActivityThread.java:3415)
5465 E AndroidRuntime: 	at android.app.ActivityThread.access$1200(ActivityThread.java:202)
5465 E AndroidRuntime: 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1676)
5465 E AndroidRuntime: 	at android.os.Handler.dispatchMessage(Handler.java:107)
5465 E AndroidRuntime: 	at android.os.Looper.loop(Looper.java:198)
5465 E AndroidRuntime: 	at android.app.ActivityThread.main(ActivityThread.java:6729)
5465 E AndroidRuntime: 	at java.lang.reflect.Method.invoke(Native Method)
5465 E AndroidRuntime: 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
5465 E AndroidRuntime: 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
5465 E AndroidRuntime: Caused by: java.lang.IllegalStateException: Not allowed to start service Intent { cmp=com.example.tobiastrumm.freifunkautoconnect/.NotificationService (has extras) }: app is in background uid UidRecord{52b1103 u0a210 RCVR idle change:uncached procs:1 seq(0,0,0)}
5465 E AndroidRuntime: 	at android.app.ContextImpl.startServiceCommon(ContextImpl.java:1589)
5465 E AndroidRuntime: 	at android.app.ContextImpl.startService(ContextImpl.java:1544)
5465 E AndroidRuntime: 	at android.content.ContextWrapper.startService(ContextWrapper.java:664)
5465 E AndroidRuntime: 	at android.content.ContextWrapper.startService(ContextWrapper.java:664)
5465 E AndroidRuntime: 	at android.support.v4.content.WakefulBroadcastReceiver.startWakefulService(WakefulBroadcastReceiver.java:99)
5465 E AndroidRuntime: 	at com.example.tobiastrumm.freifunkautoconnect.BootCompletedReceiver.onReceive(BootCompletedReceiver.java:16)
5465 E AndroidRuntime: 	at android.app.ActivityThread.handleReceiver(ActivityThread.java:3406)
5465 E AndroidRuntime: 	... 8 more

Additional info:
I am using Freifunk AutoConnect 0.9 from F-Droid repository on an Android 9 (Patchlevel 2019-03) Nokia 5 (HMD Global TA-1053).