systemctl status minecraft.service
● minecraft.service - Start Minecraft
   Loaded: loaded (/etc/systemd/system/minecraft.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2019-07-16 17:16:54 UTC; 6min ago
  Process: 1026 ExecStart=/usr/bin/screen -Dm -S minecraft /usr/bin/java java -server -Xms1024M -Xmx4096M -XX:+UseG1GC -Dsun.rmi.dgc.server.gcInt
 Main PID: 1514
    Tasks: 0 (limit: 4915)
   CGroup: /system.slice/minecraft.service

Jul 16 17:16:46 mc_server systemd[1]: Starting Start Minecraft...
Jul 16 17:16:54 mc_server systemd[1]: Started Start Minecraft.

dom@mc_server:~$ screen -r minecraft
There is no screen to be resumed matching minecraft.