Home internet service IPv6 traffic is all filtered even when using a Netgear LTE router. No port forwarding. Plz fix!

I've read much on the IPv4 / IPv6 and the 464XLAT versus dual layer etc.  What nobody has specifically stated is, why do the VPN's work when using the Franklin T9 LTE hotspot or the ASKEY LTE Gateway but NOT when using the Nokia 5G gateway.  What is different about the implementation?  Isn't the 464XLAT used on the network side regardless of the gateway?

It seems like the carrier made a decision to filter with this particular gateway to avoid people setting up servers etc. due to the "unlimited data" but this has also hampered work from home for some people and also crippled XBOX party chat.  If it's a decision that will never change, fine but TMO needs to be up-front about it.