There are a pile of assumptions I have to make here, so I will try my best.
Since you have a new ISP, you have a new router, due to the new router, I assume another IP scheme. So you had to change the IP address of the printer in order to be able to print again.
So you changed the IP address and print started working.
The reasons for scan failing could be multiple though. I am going to discount completely that the mail server the printer sends email through was provided by the ISP you no longer use, and will stick to the idea that it was Gmail/Office365 or some other that has no ties to the ISP.
So it would appear that you can reach the printer, but it can't reach out to anywhere. This would also mean you should have a fault at the printer about Unable to communicate with Xerox Smart eSolutions server.
That would be happening because your gateway is different (the address of your router) and possibly your DNS server has changed.
Having no idea what you use for PC's or Macs, I will assume Windows and keep everything generic to all versions.
Let's find the gateway and your DNS server address.
Click on the Start Menu and type cmd then the enter key (you don't have to click anything more than the start menu)
It will open the command prompt.
In that window type ipconfig/all and then the enter key
You will need to scroll through and find 2 things, the Default Gateway and the DNS Server (In yellow, and yes I did have to obscure my addresses)
Now with those 2 pieces of information, you should be able to get the printer communicating again.
Open Internet Explorer and put the IP address of the printer in the address bar and hit the enter key to load CWIS (The IP is shown on the printer when you hit the Machine Status button, probably listed as IPv4)
Now select the Properties tab at the top (if prompted to login the credentials should be username = admin, password = 1111)
On the left, select Connectivity > Setup and select the Edit for the Wired Connection
Click Edit for the IP (Internet Protocol)
Then you would need to go into the sections for IPv4 settings as well as DNS
Make sure the Gateway address is correct and then go into the DNS settings and make sure the DNS Server addresses are right, if they look right, if you want to add more you can use Googles DNS servers, which are 8.8.8.8 and 8.8.4.4 , but they won't help with anything inside of your network, just with things on the internet.