Unable to use T-Mobile Home Internet with work VPN, any suggestions?

I'm glad I'm not alone in this boat. For me, this started Friday morning 0830 19Jan2024. I have used this service with Cisco Anyconnect and a Meraki z3 for over a year and a half. I have been a Tmobile home internet customer for over 2 years.  Its pretty much my only option. 

If you're told by T mobile to call your company's help desk. You can, but they'll be stumped, all the way up to the network engineers.

For context, I’m Tier 2 Help Desk for a hospital network with 25,000 users and I’ve used Tmobile home internet exclusively for over a year and a half.  

I started having this problem on 19Jan as I use a Meraki Z3 to connect to my work network, with Cisco Anyconnect as a backup VPN.  I know there are threads 2 years old about Tmobile having issues with the Meraki but I personally have not. And I had used it for a year and a half with rarely a hick-up. Everything came to a screeching halt at about 0830 Friday morning.  I excused myself from my job to power cycle my devices, thinking Tmobile was slow and power cycle to a new IP. No dice. I lost ALL Meraki connection. Yet the Meraki light showed it was connected.  I switched over to my home wifi and connected to Cisco Anyconnect, but the connection was slow. Roughly 10/2 as opposed to 60/10 outside of VPN. I disconnected from wifi and plugged a direct network cable in. NO connection. I overnighted a network cable from Amazon (I needed a 20 ft). Still NOTHING with a wired connection.  

I then placed a warranty claim on my gateway as it was the old 4g white router. Tmobile overnighted a Nokia (trashcan) 5g router.  STILL no wired connection.  And slow wifi with VPN. By this time I had researched reddit and forums and all were coming down to the conclusion with IPv4  vs IPv6 address conflicts. 100% on Tmobile's side.  But no one at their help desk knew what the heck I was talking about. If I could see their faces, they would probably look at me like I was crazy. I broke out knowledge and experience, and I was shut down like I was speaking a foreign language. 

The guru on my ITS network team in charge of the Meraki Z3 routers mentioned that send and receive are being sent on entirely different ports and the ‘receive’ ports are changing, leading to time outs and bad connections. 

This also affects security cameras like Ring and VOIP phone services.  This will affect a lot of work from home people that talk on a virtual phone like Cisco Jabber or a Cisco IP desk phone.  

This is a SERIOUS issue that is going to drive a lot of people to change service as they can no longer use it for a TRUSTED work from home internet connection.  I do hope T mobile scrapes these forums for ideas and user feedback. If not, a lot of people are going to find alternatives; or lose their jobs. 

Personally, like others; I will be spending the weekend searching for another work alternative. My only other option is US Cellular's home internet. And I'm not impressed with their ping times. If ping times are like my phone (150ms), it won't even do a Zoom meeting. 

Tmobile was the golden goose that allowed me to live my rural country life while still having a taste of modern internet.  This is no longer the case when it comes to my job security.