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

I am supporting a user with a new S21, Can't connect with Global VPN client on a laptop tethered to the phone.  The sim card in another device works this way, and their previous phone, an S10 worked this way.  
I have tried all the methods mentioned.  But through testing I have determined for sure that the packets are not arriving to the Sonicwall at all.   The other interesting thing is that on the phone, if you download the GVPN app, it connects on the phone no problem.  But when a laptop is tethered, it goes around that VPN client on the phone and doesn't work.  It appears that the phone itself is blocking or somehow that phone on the T-Mobile network is blocking ports 500/4500 only on the hotspot connection. 
This user needs to use their phone as a hotspot and connect their business laptop to their office VPN connection. 
I have not found a solution yet.