Script hangs only when started via SystemD - apache-kafka

Question

I am trying to start the Kafka Connect component alongside Cloudera and want to wrap the Kafka Connect startup script in a systemd service file such that it can start on boot once the Cloudera services start.
For some strange reason if I start this script outside of systemd it works just fine, but when I start it via systemctl start kafka-connect it just hangs at the following log entry lines.
[Unit]
Description=Kafka Connect - Distributed
After=network.target cloudera-scm-agent
[Service]
Type=forking
ExecStart=/bin/bash -c "/app/cloudera/parcels/KAFKA/lib/kafka/bin/connect-distributed.sh -daemon /app/cloudera/kafka-connect/connect-distributed.properties"
SuccessExitStatus=143
[Install]
WantedBy=multi-user.target
2019-07-18 13:40:27,962 INFO (main) [ConnectDistributed(main:69)] Scanning for plugin classes. This might take a moment ...
2019-07-18 13:40:27,992 INFO (main) [DelegatingClassLoader(registerPlugin:184)] Loading plugin from: /app/cloudera/kafka-connect/plugins/splunk-kafka-connect.jar
2019-07-18 13:40:27,993 DEBUG (main) [DelegatingClassLoader(registerPlugin:191)] Loading plugin urls: [file:/app/cloudera/kafka-connect/plugins/splunk-kafka-connect.jar]
2019-07-18 13:40:29,206 DEBUG (main) [VersionUtils(getVersionFromProperties:63)] found git version string=v1.1.0 in version.properties file
2019-07-18 13:40:29,219 INFO (main) [DelegatingClassLoader(scanUrlsAndAddPlugins:207)] Registered loader: PluginClassLoader{pluginLocation=file:/app/cloudera/kafka-connect/plugins/splunk-kafka-connect.jar}
2019-07-18 13:40:29,220 INFO (main) [DelegatingClassLoader(addPlugins:136)] Added plugin 'com.splunk.kafka.connect.SplunkSinkConnector'
2019-07-18 13:40:29,220 INFO (main) [DelegatingClassLoader(addPlugins:136)] Added plugin 'org.apache.kafka.connect.storage.StringConverter'
My next thought was to try something a bit simpler and just create an init.d script at /etc/init.d/kafka-connect which works fine because it is nothing more than a shell script wrapper UNTIL I source in the /etc/init.d/functions file which causes this to be started via systemd again.
Two main questions -
What does systemctl do differently than a regular shell script that would cause this shell script (which in turn launches a java process) to hang at that exact same step everytime.
If my /etc/init.d/kafka-connect script works, is it okay to use on RHEL7? If so, is there a way to load that init.d script on boot of the server?
Thanks in advance!