added sdk loaded check in run callbacks

Author: ashleysmithTTD

src/callbackManager.ts

@@ -53,6 +53,8 @@ export class CallbackManager {
   public runCallbacks(event: EventType, payload: CallbackPayload) {
     if (event === EventType.InitCompleted) this._sentInit = true;
     if (event === EventType.SdkLoaded) CallbackManager._sentSdkLoaded[this._productName] = true;
+    // if SDK has not been loaded yet, callbacks should not run
+    if (!CallbackManager._sentSdkLoaded[this._productName]) return;
 
     const enrichedPayload = {
       ...payload,