Hi Brian, thanks I'll have a look at the logs if I can find them.
the htaccess file on mine shows the RewriteBase but also has all of the below on it too as I believe it's to do with the SSL Certificate from Let's Encrypt.
##### START CubeCart .htaccess #####
## File Security
<FilesMatch "\.(htaccess)$">
Order Allow,Deny
Deny from all
</FilesMatch>
#### Apache directory listing rules ####
DirectoryIndex index.php index.htm index.html
IndexIgnore *
#### Rewrite rules for SEO functionality ####
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
######## START v4 SEO URL BACKWARD COMPATIBILITY ########
RewriteCond %{QUERY_STRING} (.*)$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !^/[0-9]+\..+\.cpaneldcv$
RewriteCond %{REQUEST_URI} !^/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/[0-9a-zA-Z_-]+$
RewriteRule cat_([0-9]+)(\.[a-z]{3,4})?(.*)$ index.php?_a=category&cat_id=$1&%1 [NC]
RewriteCond %{QUERY_STRING} (.*)$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !^/[0-9]+\..+\.cpaneldcv$
RewriteCond %{REQUEST_URI} !^/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/[0-9a-zA-Z_-]+$
RewriteRule prod_([0-9]+)(\.[a-z]{3,4})?$ index.php?_a=product&product_id=$1&%1 [NC]
RewriteCond %{QUERY_STRING} (.*)$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !^/[0-9]+\..+\.cpaneldcv$
RewriteCond %{REQUEST_URI} !^/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/[0-9a-zA-Z_-]+$
RewriteRule info_([0-9]+)(\.[a-z]{3,4})?$ index.php?_a=document&doc_id=$1&%1 [NC]
RewriteCond %{QUERY_STRING} (.*)$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !^/[0-9]+\..+\.cpaneldcv$
RewriteCond %{REQUEST_URI} !^/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/[0-9a-zA-Z_-]+$
RewriteRule tell_([0-9]+)(\.[a-z]{3,4})?$ index.php?_a=product&product_id=$1&%1 [NC]
RewriteCond %{QUERY_STRING} (.*)$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !^/[0-9]+\..+\.cpaneldcv$
RewriteCond %{REQUEST_URI} !^/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/[0-9a-zA-Z_-]+$
RewriteRule _saleItems(\.[a-z]+)?(\?.*)?$ index.php?_a=saleitems&%1 [NC,L]
######## END v4 SEO URL BACKWARD COMPATIBILITY ########
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !=/favicon.ico
RewriteCond %{REQUEST_URI} !^/[0-9]+\..+\.cpaneldcv$
RewriteCond %{REQUEST_URI} !^/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/[0-9a-zA-Z_-]+$
RewriteRule ^(.*)?$ index.php?seo_path=$1 [L,QSA]
</IfModule>
## Default store 404 page
ErrorDocument 404 /index.php
##### END CubeCart .htaccess #####