Troubleshoot PostgreSQL: ‘An existing connection was forcibly closed by the remote host’

I start getting below errors, when the number of concurrent connections to azure postgresql increased to around 100, though SSL is currently disabled in azure postgres. It works fine when the number of concurrent connections are below 60, please can you suggest what could be the cause?

org.postgresql.util.PSQLException: SSL error: Remote host closed connection during handshake
at org.postgresql.ssl.MakeSSL.convert(MakeSSL.java:42)
at org.postgresql.core.v3.ConnectionFactoryImpl.enableSSL(ConnectionFactoryImpl.java:435)
at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:94)
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:192)
at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:195)
at org.postgresql.Driver.makeConnection(Driver.java:454)
at org.postgresql.Driver.connect(Driver.java:256)
at java.sql.DriverManager.getConnection(DriverManager.java:675)
at java.sql.DriverManager.getConnection(DriverManager.java:258)
at tcl_datalake_project_dataquality.tjob_dq_fullload_child_splitfile_perf_0_1.TJob_DQ_fullload_child_splitfile_perf.tDBInput_1Process(TJob_DQ_fullload_child_splitfile_perf.java:6134)
at tcl_datalake_project_dataquality.tjob_dq_fullload_child_splitfile_perf_0_1.TJob_DQ_fullload_child_splitfile_perf.tJava_3Process(TJob_DQ_fullload_child_splitfile_perf.java:21074)
at tcl_datalake_project_dataquality.tjob_dq_fullload_child_splitfile_perf_0_1.TJob_DQ_fullload_child_splitfile_perf.tDBInput_4Process(TJob_DQ_fullload_child_splitfile_perf.java:21778)
at tcl_datalake_project_dataquality.tjob_dq_fullload_child_splitfile_perf_0_1.TJob_DQ_fullload_child_splitfile_perf$8.run(TJob_DQ_fullload_child_splitfile_perf.java:24995)
Caused by: javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake