Running WordPress from a Subfolder in Azure App Service - Not Working

I’m running into an issue with my Azure App Service deployment. I have a primary PHP site running smoothly from the root directory, but I'm having trouble getting a WordPress blog to work from a subfolder (e.g., https://mydomain.com/blog).

Despite ensuring that all WordPress files are correctly placed in the site/wwwroot/mysite/blog directory, accessing https://mydomain.com/blog results in a "Not Found" error.

Here are a few details about my setup:

• The primary site is a custom PHP application.

• The application is running on Linux.

• The WordPress files are located in site/wwwroot/mysite/blog.

• I've verified that the subfolder and its contents are accessible via FTP.

• The main site and the blog use same databases.

• I have set WORDPRESS_MULTISITE_CONVERT = true and WORDPRESS_MULTISITE_TYPE = subdirectory in the Environment Variables.
• .htaccess file looks like this:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /blog/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]
</IfModule>
# END WordPress

Has anyone encountered a similar issue or have any insights on how to successfully run a WordPress site from a subfolder in Azure App Service? Any tips or configuration changes that I might be missing would be greatly appreciated!