Rufus scheduler error when using timestamp with time zone

I'm using Logstash jdbc plugin with DB2 on z/OS. Timestamp column is set to timestamp with time zone type. After initial execution of SQL statement I'm getting following error in Logstash log:

 logstash[21949]: { 2082 rufus-scheduler intercepted an error:
 logstash[21949]: 2082   job:
 logstash[21949]: 2082     Rufus::Scheduler::CronJob "0 */2 * * * Europe/Ljubljana" {}
 logstash[21949]: 2082   error:
 logstash[21949]: 2082     2082
 logstash[21949]: 2082     TypeError
 logstash[21949]: 2082     no implicit conversion of Java::JavaSql::Timestamp into String
 logstash[21949]: 2082       uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/date/format.rb:335:in `_parse'
 logstash[21949]: 2082       uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/date.rb:734:in `parse'
 logstash[21949]: 2082       /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-integration-jdbc-5.0.1/lib/logstash/plugin_mixins/jdbc/value_tracking
 logstash[21949]: 2082       /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-integration-jdbc-5.0.1/lib/logstash/plugin_mixins/jdbc/jdbc.rb:265:in
 logstash[21949]: 2082       /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-integration-jdbc-5.0.1/lib/logstash/inputs/jdbc.rb:310:in `execute_qu
 logstash[21949]: 2082       /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-integration-jdbc-5.0.1/lib/logstash/inputs/jdbc.rb:277:in `block in r
 logstash[21949]: 2082       /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/rufus-scheduler-3.0.9/lib/rufus/scheduler/jobs.rb:234:in `do_call'
 logstash[21949]: 2082       /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/rufus-scheduler-3.0.9/lib/rufus/scheduler/jobs.rb:258:in `do_trigger'
 logstash[21949]: 2082       /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/rufus-scheduler-3.0.9/lib/rufus/scheduler/jobs.rb:300:in `block in start_work_
 logstash[21949]: 2082       /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/rufus-scheduler-3.0.9/lib/rufus/scheduler/jobs.rb:299:in `block in start_work_
 logstash[21949]: 2082       org/jruby/RubyKernel.java:1442:in `loop'
 logstash[21949]: 2082       /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/rufus-scheduler-3.0.9/lib/rufus/scheduler/jobs.rb:289:in `block in start_work_
 logstash[21949]: 2082   tz:
 logstash[21949]: 2082     ENV['TZ']:
 logstash[21949]: 2082     Time.now: 2020-09-25 14:09:42 +0200
 logstash[21949]: 2082   scheduler:
 logstash[21949]: 2082     object_id: 2068
 logstash[21949]: 2082     opts:
 logstash[21949]: 2082       {:max_work_threads=>1}
 logstash[21949]: 2082       frequency: 0.3
 logstash[21949]: 2082       scheduler_lock: #<Rufus::Scheduler::NullLock:0x2497ec8c>
 logstash[21949]: 2082       trigger_lock: #<Rufus::Scheduler::NullLock:0x9817427>
 logstash[21949]: 2082     uptime: 329.846967 (5m29s847)
 logstash[21949]: 2082     down?: false
 logstash[21949]: 2082     threads: 2
 logstash[21949]: 2082       thread: #<Thread:0x684b5ba>
 logstash[21949]: 2082       thread_key: rufus_scheduler_2068
 logstash[21949]: 2082       work_threads: 1
 logstash[21949]: 2082         active: 1
 logstash[21949]: 2082         vacant: 0
 logstash[21949]: 2082         max_work_threads: 1
 logstash[21949]: 2082       mutexes: {}
 logstash[21949]: 2082     jobs: 1
 logstash[21949]: 2082       at_jobs: 0
 logstash[21949]: 2082       in_jobs: 0
 logstash[21949]: 2082       every_jobs: 0
 logstash[21949]: 2082       interval_jobs: 0
 logstash[21949]: 2082       cron_jobs: 1
 logstash[21949]: 2082     running_jobs: 1
 logstash[21949]: 2082     work_queue: 0
 logstash[21949]: } 2082 .

Are there any limitations with the use of column that is set to timestamp with timezone type in the tracking_column?