Why does the game disconnect when I am using my split tunnel VPN?

My VPN is being used and enabled for one browser only. It's not tunneling for anything else. Initially I thought the game was disconnecting with an error because of it also handling all browsers which included Edge, and thought perhaps the EA client was seeing a different IP from the game when it was checking in and thus, causing the disconnect.

But now that I've consolidated the VPN split tunneling to one browser that is not OS-based, I still get disconnected if it's on. Why?  Outside of the inconvenience, it reeks of a privacy issue.