Does Plex.tv use AWS to communicate with plex media servers?

Been trying to get my plex media server to play nice with my Cujo firewall and Asus router.
After configuring everything, I received an alert from Cujo saying someone from IP: 54.171.118.141 was trying to connect to my plex server.
Quick whois shows the IP address belongs to Amazon AWS in Ireland.
I’m assuming this is my plex server phoning home, but I wanted to make sure.

Anyone able to provide input?

Thanks

Thank you, I thought this was the case, just wanted to make sure.