It’s clear from the blocking message that plugin is not able to contact Freemius API server. You can whitelist Freemius API IP address to resolve this issue:
IP for api.freemius.com:
https://mxtoolbox.com/SuperTool.aspx?action=a:api-1122186795.us-west-2.elb.amazonaws.com&newAppVersion=1
IP for wp.freemius.com:
https://mxtoolbox.com/SuperTool.aspx?action=a:wp.freemius.com&newAppVersion=1