I have found the line in the .htaccess file that causes the problem
# 6G:[REQUEST METHOD]
<ifModule mod_rewrite.c>
RewriteCond %{REQUEST_METHOD} ^(connect|debug|delete|move|put|trace|track) [NC]
RewriteRule .* - [F]
#</IfModule>
I believe that it’s the connect part of it that is the problem.
I’m going to hold of of marking this resolved until I’m 100% positive as to the EXACT word that is the problem child.
Actually, I reposted under plug-ins and hacks for All In One WP Security & Firewall
since the woocommerce rest-api works fine without the firewall plug-in. Also it’s only one portion of the plug-in that is causing the problem.