Current ip address as i see is 52.40.43.31 but I am not sure if it is static.
What you see in cPanel for ip is for different purpose. From those ips user will not be able to access your website. But we need to access api.freemius.com from your website.

Did you show full message to SiteGround support? You can also tell them to check if cURL also working correctly or not. You can follow this troubleshoot https://fooplugins.com/documentation/foogallery/troubleshooting-foogallery/freemius-api-connectivity/