AiMesh node connection issues between wired devices

[nihon]

Hi
I have

Asus AC2900 (sames as AC86U) as main router.
I have an old AC68U setup as AiMesh node.
Both on Asus merlin ROM.

On the AiMesh node I have one desktop computer attached using a wired connection and a laptop connected to the node also using a wired connection.
When I remote desktop from the desktop to the laptop I every now and then lose the connection, even though both computers are wired connected to the same node that support Gigabit speed wired connection.

I assume the problem is that the actual data goes from desktop -> Ai mesh node (AC68U) -> Main router (AC2900) -> Ai mesh node (AC68U) -> laptop.
Is that assumption correct?

Is there anyway one can force two computers connected on the same AiMesh node to communicate directly in such scenario.
Both computers obviously need internet access out through the main router still, but for a remote desktop instance using local IP I don't see why the communication could not be direct...

Any input on how to get rid of the dropouts would be welcome.

Johan