I have made the .htaccess changes in /public/legacy
RewriteBase /public/legacy
I had the siteurl as main.com
I changed this to https://main.com and it now seems to be rewriting correctly
What I think may have been happening was that the rewrites for the main site (for which this is a subdirectoyr) were being applied first to add the www etc and then the rewrites for Suite wer kicking in as well hence resolving the URL twice