VPN (SonicWall) will not connect over T-mobile 5G Hotspot

ntdriverman wrote:

I found a post about turning off IPv6 on my WiFi connection on my Windows laptop that resolved this issue for me.

The issue I was having was that from my Windows laptop, I was NOT able to VPN into my workplace using my personal hot-spot thru my iphone 12 (I’m running iOS 15.1.1) using TMOBILE.

To resolve the issue, I had to disable IPv6 on my Wireless connection on my laptop.

Do disable IPv6 on my Wireless connection on my Windows laptop I did these steps:

1. Open “Network and Internet Settings”
2. Under “Advanced Network Settings”, Click on “Change adapter options”
3. It will bring up a list of Network connections, double click on the one that says “Wi-Fi”
4. In the new dialog box, click on “Properties” bottom left, do NOT click on “Wireless Properties”
5. The next dialog box will have a list of "This connection uses the following items”
6. Scroll down in that list to find “Internet Protocol Version 6 (TCP/IPv6)”, this will be in the list after the “Internet Protocol Version 4 (TCP/IPv4)”.
7. Uncheck the box in front of "Internet Protocol Version 6 (TCP/IPv6)". Leave the IPv4 checked.
8. Hit “OK”

After I did these steps I was able to use the VPN client (in my case it is the FortiClient VPN) and I was able to successfully VPN thru my hot-spot thru my TMOBILE service.

I also went back and retested using a normal WiFi connection (thru my home network) and everything still worked in that case too.

As of yesterday, for me, this is no longer an option.  It appears that you can not disable IPv6 on a wifi connection. It completely looses connection.  Also unable to use ZScaler OR PIA VPN services.

Unfortunately I am going to have to leave T-Mobile over this.
Anyone else run into this just recently?