Some YouTube embeds don't load in Reader

Expected behavior

All embedded YouTube videos that play on the web also play in Reader in the app.

Actual behavior

Only some embedded YouTube videos that play on the web also play in Reader in the app.

Actual	Expected

Steps to reproduce the behavior

1. In a WordPress blog on the web, paste these two video URLs into a new post:
   • Video A: https://www.youtube.com/watch?v=mNEUkkoUoIA
   • Video B: https://www.youtube.com/watch?v=jNQXAC9IVRw
2. Expect: Loading the post on the web shows the videos embedded and playable
3. In Reader in the app, follow the blog from step 1 and load the post
4. Observe:
   • Video A: Shows a message "Video unavailable".
   • Video B: Correctly shows a playable video.
5. Expect: Tapping the globe icon at the top of the UI opens a web view that properly plays both videos.

Research

• This LOC may be related.
• Applying the patch below loaded the embeds properly:

diff --git a/WordPress/Classes/ViewRelated/Reader/Detail/WebView/ReaderWebView.swift b/WordPress/Classes/ViewRelated/Reader/Detail/WebView/ReaderWebView.swift
index e395fb95af..91a101570e 100644
--- a/WordPress/Classes/ViewRelated/Reader/Detail/WebView/ReaderWebView.swift
+++ b/WordPress/Classes/ViewRelated/Reader/Detail/WebView/ReaderWebView.swift
@@ -28,7 +28,7 @@ class ReaderWebView: WKWebView {
 
         let content = formattedContent(addPlaceholder(string), additionalJavaScript: additionalJavaScript)
 
-        super.loadHTMLString(content, baseURL: Bundle.wordPressSharedBundle.bundleURL)
+        super.loadHTMLString(content, baseURL: postURL ?? URL(string: "https://www.wordpress.com")!)
     }
 
     /// Given a HTML content, returns it formatted.

Note: Patch was applied to aa1d441040bd970878e2d427806cbd318fbbc76d
Note 2: Patch is only for demo purposes, the nil string fallback URL (www.wordpress.com) is probably not the best choice.

Tested on iPhone 12, iOS 16.2, WPiOS 21.6

Start in WordPress/Classes/ViewRelated/Reader/Detail/WebView/ReaderWebView.swift at loadHTMLString and inspect how postURL and the bundle URL are used as the base URL. Reproduce the issue with Video A and Video B in Reader, then verify both play in the embedded view while the globe web view remains functional.