Connecting to VPN ignores all local DNS setup

I have some services running on a local server behind a reverse proxy and those services are protected from access outside IP subnets not specified in the reverse proxy settings.

In my local router, I have the addresses for all these services listed and set to point to my local reverse proxy rather than circle out to the net and back. This keeps my IP local and therefore I am able to access the protected services.

This works great until I connect to my office's VPN via Sophos Connect. When I connect to that, I'm assuming my PC only uses the DNS servers on the VPN and therefore doesn't get that local route to my reverse proxy. So it circles out to the net, gets my external IP, and hits my local protected services and is rejected.

I need to connect to my office VPN to access resources on that network, but I don't need all my traffic hijacked by the VPN. Is there some way to have my LAN and my VPN connections coexist?

Or can I somehow add my local DNS server to the list of servers that the VPN uses?

Thanks!