The address changing is normal.
Jaxx is an HD (hierarchical deterministic) wallet, which means it generates a new address every time you receive digital assets to your Jaxx Wallets as a way of keeping your balance private.
You can see all of the addresses generated by Jaxx in MENU > Tools > Display Private Keys > (I UNDERSTAND)
You can use any of the previously generated addresses to receive digital assets anytime and without any issue.
PS. We have disabled HD for Ethereum as of Jaxx version 1.2.13 - More on this here
Disclaimer: Please make sure you do not share your private keys with anyone, including Jaxx User Success team, as if someone gains access to them, they will also be able to manage your digital assets.