Warp Split Tunnel and L2TP VPN quitting

We need to run WARP alongside an L2TP VPN (in Exclude mode). We’ve therefore configured split tunnel as per this doc: https://developers.cloudflare.com/cloudflare-one/connections/connect-devices/warp/exclude-traffic/split-tunnels/

When WARP is active though the VPN quits within a couple seconds after connecting. If you temporarily disconnect Warp the L2TP VPN is fine. Any ideas?

Maybe some traffic for your L2TP VPN is still going via Warp, Is it working when Warp is in include mode?
Please check if you have followed the steps mentioned in the below article as well.