ADDITIONAL SYSTEM INFORMATION :
macOS 10.15.5

$ java -version
java version "11.0.8" 2020-07-14 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.8+10-LTS)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.8+10-LTS, mixed mode)

A DESCRIPTION OF THE PROBLEM :
This happens with 11.0.8 only on macOS. 16-ea is fine as well as 11.0.8 on Linux.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
javac DateFormatterBug.java
java DateFormatterBug

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
2019-05-02T01:02:03
ACTUAL -
Exception in thread "main" java.time.format.DateTimeParseException: Text '05/02/2019 01:02:03 AM' could not be parsed at index 20
at java.base/java.time.format.DateTimeFormatter.parseResolved0(DateTimeFormatter.java:2046)
at java.base/java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1948)
at java.base/java.time.LocalDateTime.parse(LocalDateTime.java:492)
at DateFormatterBug.main(DateFormatterBug.java:8)

---------- BEGIN SOURCE ----------
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class DateFormatterBug {
    public static void main(String[] args) {
        String date = "05/02/2019 01:02:03 AM";
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("MM/dd/yyyy hh:mm:ss a");
        LocalDateTime result = LocalDateTime.parse(date, formatter);
        System.out.println(result);
    }
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Use JDK 16-ea:

$ java -version
openjdk version "16-ea" 2021-03-16
OpenJDK Runtime Environment (build 16-ea+7-249)
OpenJDK 64-Bit Server VM (build 16-ea+7-249, mixed mode, sharing)
$ java DateFormatterBug
2019-05-02T01:02:03

FREQUENCY : always