Cannot use connector with master=local[N]

[dolfinus]

I'm trying to use this connector with Spark session created using .master("local[2]") to write data to GP in 2 parallel connections instead of just one. Unfortunately, I've got errors like:

insert ... from ext2563ed72a064489dab799d61e85532a3_0' failed, ERROR: invalid input syntax for type date: "2024-"  (seg40 slice1 my-seg-01:10000 pid=57946)
  Where: External table ext2563ed72a064489dab799d61e85532a3_0, line 9831 of gpfdist://myhost:49152/output.pipe, column file_date
ERROR [gpfdist-write2563ed72-a064-489d-ab79-9d61e85532a3]: ERROR: current transaction is aborted, commands ignored until end of transaction block
Exception in thread "gpfdist-write2563ed72-a064-489d-ab79-9d61e85532a3" java.lang.Exception: writeUUID=2563ed72-a064-489d-ab79-9d61e85532a3 timeout on waiting job completion
        at com.itsumma.gpconnector.writer.GreenplumBatchWrite$SqlThread.run(GreenplumBatchWrite.scala:280)
        at java.base/java.lang.Thread.run(Thread.java:1623)

And writing is just stuck.

This is info from Spark UI, Executors menu item:

Executors are stuck in this lock:

• spark-greenplum-connector/spark-greenplum-connector/src/main/scala/com/itsumma/gpconnector/rmi/RMISlave.scala

  Line 306 in 0d23a6d

  localWriteBufferGuard.synchronized {

• https://github.com/itsumma/spark-greenplum-connector/blob/spark3/spark-greenplum-connector/src/main/scala/com/itsumma/gpconnector/rmi/RMISlave.scala#L329

Both are waiting for writing current status to RMI Master, but none of them could do this. But if I start Spark session with just one executor, or use df.coalesce(1), this error does not reproduce.