Here is the solution to anyone having same problem:
Need to broaden regex to include more characters. ([\w-]+) includes letters, numbers and dashes.
So this is what you want in htaccess:
RewriteEngine On
RewriteCond %{THE_REQUEST} [1]{3,9}\ /. index\ HTTP/
RewriteRule ^(. )index$ http://YOURWEBSITE.COM/$1 [L,R=301]
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([^/]+)/$ http://YOURWEBSITE.COM/$1 [L,R=301]
RewriteCond %{THE_REQUEST} [2]{3,9}\ /(.+).html\ HTTP/
RewriteRule ^(.+).html$ http://YOURWEBSITE.COM/1 [L,R=301] RewriteRule ^([\w-]+) /$1.html [L]