RuntimeError: function signature mismatch when invoking a generic delegate

[jeromelaban]

Given the following extension:

public static class FuncMemoizeExtensions
{
    public static Func<TParam, TResult> Test<TParam, TResult>(this Func<TParam, TResult> func)
    {
       return v => default(TResult);
    }
}

and the following code :

Func<int, int> a = i => i;
var a2 = a.Test();

a(1);
a2(1);

a(1) is executed properly, where a2(1) fails in chrome with the following error:

wasm-02396cee-9252:212 Uncaught (in promise) RuntimeError: function signature mismatch
    at hello_wrapper_delegate_invoke_System_Func_2_int_int_invoke_TResult_T_int (wasm-function[9252]:488)
    at hello_Hello_Main_string__ (wasm-function[9235]:1459)
    at mscorlib_wrapper_unknown_object_gsharedvt_out_sig_intptr_object__intptr_2 (wasm-function[18376]:40)
    at mscorlib_wrapper_runtime_invoke_object_runtime_invoke_sig_void_intptr_intptr_intptr_object_intptr_intptr_intptr (wasm-function[18034]:164)
    at mono_llvmonly_runtime_invoke (wasm-function[6921]:1024)
    at mono_jit_runtime_invoke (wasm-function[6678]:1025)
    at do_runtime_invoke (wasm-function[2044]:213)
    at mono_runtime_try_invoke (wasm-function[2158]:196)
    at do_try_exec_main (wasm-function[6592]:257)
    at mono_runtime_try_exec_main (wasm-function[6589]:78)
    at mono_runtime_try_run_main (wasm-function[6586]:154)
    at mono_jit_exec (wasm-function[6585]:300)
    at mono_wasm_main (wasm-function[9226]:424)