iCloud Private Relay No Longer Supported After Installing New TMO Router

Here is a screenshot

 

T-Mobile Not Compatible with iCloud Private Relay

I have same issue as well. Is there any solution?

Yes, I solved this problem for my business account and my solution is applicable for only business accounts.

It turns out that by default T-Mobile does indeed filter all business Internet accounts using the 5G gateway that I have (TMO-G4SE 5G Gateway) and perhaps others.  The reason for the filtering is to prevent employees from visiting certain types of websites.  (Use your imagination to figure out the kind of sites I'm referring too.)

Unfortunately, the business account owner can not turn off this filtering.  Only T-Mobile can turn it off.

Contact T-Mobile technical support for business accounts at +1 877.347.2127, describe the problem, and tell the representative that you want to turn off the filtering. 

In my case, the representative did not know about this filtering, told me that it was an Apple problem, and transferred me to an Apple support person who did all kinds of testing with me and then told me it was a T-Mobile problem.  I'd spent two hours on the phone and had no progress to show for it.  I was very frustrated.  An hour later when I received a the standard follow-up text from the T-Mobile to rate the quality of the T-Mobile tech support representative, I left a bad rating.  Two days later someone from T-Mobile technical support called me.  He understood the problem, knew about the filtering, turned it off in just a few minutes, and iCloud Private Relay immediately worked on all my devices.  

The moral of this story is that when you call, if the T-Mobile technical support representative doesn’t know about the filtering then ask to speak to a level 2 support person and keep escalating until you speak to someone who knows about it.  

Good luck.

- nello