I’d be curious what ISP.  I have up to 12 test versions of server os’s running in esxi or proxmox at any given time.

J

You can use the latest 12.3 release as it is supported on Windows 10/11.  Check here - System Requirements - User Guide for VMware vSphere

How is your ISP aware of what OS you’re using? I’ve never heard of that happening, I’d love to know more about why that happened.

To answer your question directly, the latest release of Veeam version 12 is supported on Microsoft 10 and 11.

+1 on what your ISP is seeing. I run 2 instances of Proxmox and have several VBR Servers at home in my lab. I also back up my entire network (well, what I can). your ISP shouldn’t have any say in this if you are internal to your own network. 

. Their residential service terms of service (TOS) are designed for typical home use, not for hosting servers that provide content or services to people outside your local network

Xfinity: 
use or run dedicated, stand-alone equipment or servers from the Premises that provide network content or any other services to anyone outside of your Premises local area network (“Premises LAN”), also commonly referred to as public services or servers. Examples of prohibited equipment and servers include, but are not limited to, email, web hosting, file sharing, and proxy services and servers;

use or run programs, devices, or equipment from the Premises that provide network content or any other services to anyone outside of your Premises LAN, except for your personal and non-commercial residential use;

My wife works from home.  She is a web programmer for news paper parent company.  I don’t want to risk having my internet down for a few days because I installed a server.  

VEEAM 11 works on Windows workstation.   I saw that they dropped support on VEEAM 13.  

Yes there were many things deprecated in Version 13.  See this forum post - eV13] Deprecated and Discontinued features for our 2025 release - Page 2

I guess I will be able to get to VEEAM 12.3 CE.  It has Proxmox VE support.  VMWare 6 support.   I recommand VEEAM CE to my tech friends online with home labs.   Not sure what happens when 12.3 disappears.  

Then you need to upgrade technology with it.  

Home ISPs have rules against running Windows Servers.   I will check with ATT Fiber and Xfinity to see if I can run a Windows Server for VEEAM backup within their policy.   Last time I tried, I was offline from the internet for 3 days after I shut it down.

Don't expose your server publicly. 

If you are trying to back up resources within your home network anyway, it shouldn't need to be public.