For others running into this problem the issue appears to be that Powerpress strips the headers and causes issues with remote authorization. I solved it in the htaccess file with the following code.
# BEGIN attempting to rewrite the auth header
<IfModule mod_rewrite.c>
# Pass Authorization headers to an environment variable
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
</IfModule>
# END attempting to rewrite the auth header