Request exceeded the limit of 10 internal redirects due to probable configuratio

Having an issue with this, and can’t seem to find the fix.
I have a multi-network site on rhel 7.9. Most stuff I find refers to the .htaccess file.
This is my current file:
RewriteEngine On
RewriteBase /

#uploaded files
RewriteRule ^(.*/)?files/$ index.php [L]
RewriteCond %{REQUEST_URI} !.*wp-content/plugins.*
RewriteRule ^(.*/)?files/(.*) wp-includes/ms-files.php?file=$2 [L]

# add a trailing slash to /wp-admin
RewriteCond %{REQUEST_URI} ^.*/wp-admin$
RewriteRule ^(.+)$ $1/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule . – [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-.*) $2 [L]
#RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ – [L]
RewriteRule . index.php [L]

<IfModule mod_security.c>
<Files async-upload.php>
SecFilterEngine Off
SecFilterScanPOST Off
</Files>
</IfModule>

I have 1 line commented, and it seems to have stopped the message, according to logs. Ultimately, this came about as an admin was trying to add users to her site, and it wasn’t allowing her to do so. Which is another topic, though the 2 might be related in some way.

Is there a better way to control this rewrite error? Keeping in mind that I can’t fix 1 site while breaking another.