Logstash JVM Heap Errors (Not Allocating to Xms)

I'm using logstash 7.10. I have 3 pipelines with 3 different input sources. Two out of the three stop producing output after a short number of documents. One of them runs fine. If I try to run logstash with all 3 specified in the pipelines.yml file, logstash eventually errors out with Logstash - java.lang.OutOfMemoryError: Java heap space. I have both Xms and Xmx in /etc/logstash/jvm.options set to half of my ram (4g), but I am only seeing my system using 1g of ram.

This is first bit of the cmdline shown with ps shows the Xms and Xmx values are set correctly:

root      2341 11.3 11.4 6957772 934508 pts/0  Sl+  09:26   1:39 /usr/share/logstash/jdk/bin/java -Xms4g -Xmx4g -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -Djava.awt.headless=true -Dfile.encoding=UTF-8 -Djruby.compile.invokedynamic=true -Djruby.jit.threshold=0 -Djruby.regexp.interruptible=true -XX:+HeapDumpOnOutOfMemoryError