AnyConnect VPN has become too slow as of Sep 2024

I use Tmobile 5G internet and my AnyConnect VPN speeds were adequate until Sep 2024!

The VPN speeds are now at best about 4 mbits/sec for download and about 6 mbit/sec upload, which is way too slow.

The nominal speed, without VPN, for my Tmobile 5G internet, is more than 300 mbits/sec download speeds.

What has changed and how do I resolve this?