Java Refection : NoSuchMethodException on high load

I am getting below exception ONLY when high load is running like 25 calls (same scenario) per second and it is not coming for every call, it is coming for few times only.However, when I run few calls at a time i am not getting this exception. I checked that method public execute method exists in com.abc.block.Rules class and this is the reason exception is not coming when i run few calls.

02 Oct 2019 02:00:01,021 [Worker[23]] ERROR [SNode] 80] NoSuchMethodException during reflective call on class com.abc.block.Rules java.lang.NoSuchMethodException: com.abc.block.Rules.execute(com.abc.common.cdata) at java.lang.Class.getMethod(Class.java:1786)

While running load reflection is not working correctly. Any inputs please ?

Code :

    Object port = service.getClass()
            .getMethod(xmlSNode.getPortMethodName()).invoke(service);

    outResult  = port
                 .getClass()
                 .getMethod(xmlSNode.getOperation().getName(),
                         inputs.getInputTypes())
                 .invoke(port, data);

Rule call :

public Object[] execute(cdata c) throws Exception{
...
}

Any input please