Call DLL written in Delphi from Java

I have a simple DLL written in Delphi 10.4. When I call the DLL from another Delphi application, everything works 100%, but when I call the same DLL from a Java application (using JNA) I get strange results.

I initially declared my DLL input parameters of type PChar. When I call the DLL from the Java app, I get funny characters inside my DLL. I changed it to ShortString, but then I loose the first character of the string in my DLL. I probably need to do some datatype casting in Java but I cannot find out what. Can somebody perhaps help?

Here is a sample DLL in Delphi to demonstrate:

procedure TestDataTypes(PCharVar: PChar; ShortStringVar: ShortString); stdcall;
begin
  ShowMessage('PChar: ' + PCharVar + #13#10 +
              'ShortString: ' + ShortStringVar);
end;

exports
  TestDataTypes;

Code to call DLL from Delphi:

procedure TestDataTypes(PCharVar: PChar; ShortStringVar: ShortString); stdcall; external 'TestDataType.dll';
...
TestDataTypes(PChar('PChar Value'), 'ShortString Value');

Code to call DLL from Java:

INSTANCE.TestDataTypes("Java PChar Value", "Java ShortString Value");

Results: Top is when DLL is called from Delphi and bottom when it is called from Java:

Some Feedback: I changed the datatype in Delphi to PAnsiChar and it works on my local pc. When deployed, it worked on some client machines but not others. The error I get when I call the DLL from my Java app is "Invalid memory access". I have added logging in my DLL and it seems it does not even enter the DLL.... I have also changed the Java datatype to WString but that did not make a difference.

Delphi code:

function HasCOMConnection(COMServerName: PAnsiChar): Boolean; stdcall;
begin
  WriteLog('HasCOMConnection: 64-Bit DLL entered');
  Result := HasConnection(COMServerName);
end;

Java Call:

    private interface IPMOProcessLabResult extends com.sun.jna.Library {
        boolean HasCOMConnection(String COMServerName);
    }

    private boolean canConnectToCOMServer() {
        try {
            IPMOProcessLabResult lib = (IPMOProcessLabResult) Native.loadLibrary(config.libraryName, IPMOProcessLabResult.class);
            return lib.HasCOMConnection(config.comServerName);
        }
        catch (Exception ex) {
            new AppendLog(new Date(), this.getClass() + "\t" + ex.getClass() + "\t" + "Exception while trying to connect to COMServer: " + ex.getMessage(), "debug");
            return false;
        }
    }