FIX: Always return the latest API version requested

app/assets/javascripts/discourse.js.es6

@@ -137,7 +137,7 @@ const Discourse = Ember.Application.extend({
       Discourse.instanceInitializer({
         name: "_discourse_plugin_" + (++initCount),
         after: 'inject-objects',
-        initialize: function() {
+        initialize() {
           withPluginApi(cb.version, cb.code);
         }
       });

app/assets/javascripts/discourse/lib/plugin-api.js.es6

@@ -361,6 +361,11 @@ function getPluginApi(version) {
     if (!_pluginv01) {
       _pluginv01 = new PluginApi(version, Discourse.__container__);
     }
+
+    // We are recycling the compatible object, but let's update to the higher version
+    if (_pluginv01.version < version) {
+      _pluginv01.version = version;
+    }
     return _pluginv01;
   } else {
     console.warn(`Plugin API v${version} is not supported`);