@Obvious
Hello!
Incoming packet forwarding is a server side matter. It makes no difference whether the VPN connection is handled by OpenVPN 2,. OpenVPN 3 or Wireguard.
In Linux and macOS, Eddie can run both OpenVPN and Hummingbird, which is an AirVPN software based on OpenVPN3-AirVPN library. You can tell Eddie to run Hummingbird and not OpenVPN by ticking "Use Hummingbird" item in Eddie's "Preferences" > "Advanced" window.
On a client settings equal footing, packet forwarding behavior discrepancy between VPN servers should be investigated server side too. From your description it is possible that you're just wasting time as it appears that you're investigating incorrectly: please open a ticket. The support team can, first and foremost, ascertain whether packets are actually pre-routed and forwarded to your node or not.
Kind regards