Multisite path issue
the two issues causing this were both in the .htaccess:

this line was commented out:

RewriteBase /


and then we had to add this per subsite:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !=/favicon.ico
RewriteCond %{REQUEST_URI} ^/wikifix
RewriteRule ^ wikifix/index.php [L]


including the first 3 rules:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !=/favicon.ico
RewriteCond %{REQUEST_URI} ^/wiki
RewriteRule ^ wiki/index.php [L]


since both subsites start with /wiki, it was also important to have the RewriteCond for wikifix BEFORE the RewriteCond for wiki