VPN on ANdroid hinders Charles Schwab App

I have VPN on two PCs running WIndows 10 and two Samsung Galaxy S8s, running Android 9.0. It generally works, but I think it slows down things a bit. But the bigger problem is that it will not allow me to login to my brokerage account at Charles Schwab when it is active - it just hangs until I disable the VPN, and then the connection pops up and the account is right there.

I see similar behavior on my PC when I try to login to Bank of America - I get an incomplete load of the web pages.

Any idea how to fix this?