ERROR: Ignoring subscription to event

In GG, homescreen and launcher application are starting by systemd, now I am trying to change homescreen-service to start homescreen and launcher when system starting.
The purpose of this change was that homescreen-service can control the start sequence of applications.

When debuging I met an issue, homescreen can't receive subscribed event.
The error log please refering with hss-bug.txt at line 3167.
The changed sequence and error occured timing please refering with handshake.png and recoverApp.png.

sourcecode link:
homescreen-service
libhomescreen
libqthomescreen
homescreen
launcher

Please help checking whether there are some issues existing.