nginx/php/fastcgi: php files from secondary directories not evaluated as php

I'm running nginx-1.14.0 with php-fpm7.2. When I access php files that are resident in the root, they are properly sent through fastcgi and their php gets properly evaluated. However, when I access php files -- even with the same contents -- from within secodary site directories, they are sent back as BIN data and not sent through fastcgi to be evaluated as php.

Here are the pertinent items in my nginx config file ...

server { ... etc. ... root /usr/share/nginx/html; index index.php index.html index.htm; location / { try_files $uri $uri/ =404; } location ~ ^/(fm)(/?$|/.+\.php) { alias /usr/share/nginx/$1$2; # I get the same results with "alias $1$2;" include phpsite_params; } location ~ ^/(css|static|img|js)($|/.*) { alias $1$2; } location ~ \.php$ { include phpsite_params; } } 

The /usr/share/nginx/html/index.php file gets properly passed through fastcgi and evaluated as php when I send this URL: http://example.com.

However, the /usr/share/nginx/fm/index.php file just gets sent back to me as plain text without the php being evaluated when I send this URL: http://example.com/fm, and also this URL: http://example.com/fm/, and also this URL: http://example.com/fm/index.php.

Here are the contents of phpsite_params ...

fastcgi_split_path_info ^(.+\.php)(/.+)$; fastcgi_pass unix:/var/run/php/php7.2-fpm.sock; fastcgi_index index.php; fastcgi_read_timeout 600; include fastcgi_params; 

... and here are the contents of fastcgi_params ...

fastcgi_param QUERY_STRING $query_string; fastcgi_param REQUEST_METHOD $request_method; fastcgi_param CONTENT_TYPE $content_type; fastcgi_param CONTENT_LENGTH $content_length; fastcgi_param SCRIPT_FILENAME $request_filename; fastcgi_param SCRIPT_NAME $fastcgi_script_name; fastcgi_param REQUEST_URI $request_uri; fastcgi_param DOCUMENT_URI $document_uri; fastcgi_param DOCUMENT_ROOT $document_root; fastcgi_param SERVER_PROTOCOL $server_protocol; fastcgi_param GATEWAY_INTERFACE CGI/1.1; fastcgi_param SERVER_SOFTWARE nginx/$nginx_version; fastcgi_param REMOTE_ADDR $remote_addr; fastcgi_param REMOTE_PORT $remote_port; fastcgi_param SERVER_ADDR $server_addr; fastcgi_param SERVER_PORT $server_port; fastcgi_param SERVER_NAME $server_name; fastcgi_param HTTPS $https if_not_empty; # PHP only, required if PHP was built with --enable-force-cgi-redirect fastcgi_param REDIRECT_STATUS 200; 

What am I doing wrong in my configuration?

Thank you in advance for any help or suggestions.

UPDATE: I added the following section to my nginx configuration file, and it works properly. But this location doesn't use PHP, and therefore, it seems to indicate that the error is specifically related to fastcgi.

 location ~ ^/(junk)($|/.*) { alias $1$2; autoindex on; } 

Can anyone think of anything within fastcgi or php-fpm which could cause the problem that I'm having?