Could my server's IP be blocked by wordpress.org API?

Question

As per title: Would it be possible that my server's (RHEL BASED with Plesk) IP address is being blocked / blacklisted or throttled by Wordpress.org?

I have a webserver that hosts a fair bit of Wordpress website that have shown Time To First Byte (TTFB) upwards of 6 seconds since 2 days ago.

What I did

• Tested non-wordpress websites on same server
• I have installed Query Monitor Plugin to debug slow performance which showed that the api.wordpress.org API calls were hitting timeouts
• I have tried to ping api.wordpress.org from my server:

PING api.wordpress.org (198.143.164.251) 56(84) bytes of data.
--- api.wordpress.org ping statistics ---
16 packets transmitted, 0 received, 100% packet loss, time 15341ms

• I have tried cUrl with no results as suggested here (https://wordpress.org/support/topic/i-cant-ping-or-contact-api-wordpress-org/)

Hope someone here can help!