Hello,
Today, I have the same issue as Loïc at OVH hosting.
It’s WP_Http_Curl->request() method which is called
When I debugged, I had a curl_errno = 7
[7] => ‘CURLE_COULDNT_CONNECT’
I contacted OVH support for knowing what is wrong because Elliot said to me the server’s IP isn’t blocked by his ACF host.