I use the following as the first redirection rule of the .htaccess:
RewriteCond %{REQUEST_URI} ^/(?:[0-9]+\..+\.cpaneldcv|[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?|\.well-known/acme-challenge/[0-9a-zA-Z_-]+)$
RewriteRule .* - [L,NC]
This will force the redirections to stop if there is a file match.
RewriteCond %{REQUEST_URI} ^/(?:[0-9]+\..+\.cpaneldcv|[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?|\.well-known/acme-challenge/[0-9a-zA-Z_-]+)$
RewriteRule .* - [L,NC]
This will force the redirections to stop if there is a file match.