Calling an AppCompatActivity, You need to use a Theme.AppCompat theme (or descendant) with this activity

I'm trying to call a Java Class from Unity which extends AppCompatActivity, I'm getting the error: you need to use a theme.appcompat theme (or descendant) with this activity. However I am using this as you can see below.

AndroidManifest.xml (Android Studio):

 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.MyPackage.ProjectName">
 
     <application android:theme="@style/Theme.AppCompat.Light">
         <activity
             android:name=".MyActivity"
             android:theme="@style/Theme.AppCompat.Light">
         </activity>
     </application>
 
 </manifest>

AndroidManifest.xml (Unity):

 <activity android:name="com.unity3d.player.UnityPlayerActivity" 
           android:theme="@style/Theme.AppCompat.Light" 
           android:label="@string/app_name" android:screenOrientation="fullSensor" 
           android:launchMode="singleTask" android:configChanges="mcc|mnc|locale|touchscreen|keyboard|keyboardHidden|navigation|orientation|screenLayout|uiMode|screenSize|smallestScreenSize|fontScale|layoutDirection">
           <intent-filter>
               <action android:name="android.intent.action.MAIN" />
               <category android:name="android.intent.category.LAUNCHER" />
               <category android:name="android.intent.category.LEANBACK_LAUNCHER" />
           </intent-filter>
           <meta-data android:name="unityplayer.UnityActivity" android:value="true" />
      </activity>

MyActivity.java:

 package com.MyPackage.Project;
 
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 
 public class MyActivity extends AppCompatActivity {
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
     }
 
     public void StartActivity(Activity activity)
     {
         Intent intent = new Intent(activity, MyActivity.class)
         activity.startActivity(intent);
     }
 }

CallActivity.cs

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class CallActivity : MonoBehaviour 
 {
     void Start()
     {
         AndroidJavaObject ajo = new AndroidJavaObject("com.MyPackage.Project.MyActivity");
         ajo.Call("StartActivity", ActivityClass.currentActivity);
     }
 }

ActivityClass.currentActivity is Unity's currentActivity. Either way I am getting the error about the AppCompat theme and I have no idea why. I hope it's even possible to call an AppCompatActivity from Unity cause I can't find anything about it. Hopefull someone here knows something because it would really help me out.