apache htaccess rewriterule 出现 409 错误

Question

我有这些 htaccess 规则：

Options +FollowSymLinks -MultiViews
RewriteEngine On
RewriteBase /

RewriteCond %{HTTPS} off [OR]
RewriteCond %{HTTP_HOST} ^www\. [NC]
RewriteCond %{HTTP_HOST} ^(www\.)?(.+)$
RewriteRule (.*) https://%2%{REQUEST_URI} [R=301,NE]

# 301 externally redirect all .php extensioned requests to extensionless
RewriteCond %{THE_REQUEST} ^[A-Z]{3,}\s([^.]+)\.php [NC]
RewriteRule ^ %1 [R=301,NC,N]

RewriteRule ^contact(\.php)?$ /?modal=contact [R=301,NC]

# if x.php is a file, internally add .php to x
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule !.*\.php$ %{REQUEST_URI}.php [NC,L]

哪个可以采取任何这些...

http://www.example.com/contact
http://www.example.com/contact.php
http://example.com/contact
http://example.com/contact.php
https://www.example.com/contact
https://www.example.com/contact.php
https://example.com/contact
https://example.com/contact.php

...并返回： https://example.com/?modal=contact

Note that these rules also internally resolve links like https://example.com/page to https://example.com/page.php so the user will see the URL without the extension.

虽然我在浏览器中看到了所需的结果，其中包含https://www.example.com/contact.php之类的链接，但出现 409 错误。 是什么原因造成的？

笔记：

• 我在 Google Search Console 和 wheregoes.com 中看到 409 错误
• 我在 Chrome DevTools 中只看到两个 301 状态。