Eufycams painfully slow to connect

I'm using the HomeBase 3 (connected via ethernet) with a variety of indoor and outdoor cameras - some with battery and others with wall supply.

Sometimes it takes 3-10 seconds just to connect, with the stream often freezing. Sometimes it just won't connect at all.

But if I disconnect my ISP fiber from the router, so the home internet is "offline", all of the cameras connect instantly and stream just fine.

It seems like even when I'm at home, on the same network - whether using WIFI or ethernet, the eufy app is connecting through the cloud servers instead of locally.

Is there a fix for this?