GoodCloud: No connection to other node's

We have a GL-AX1800 as the main node and a total of 4 routers in the side-to-side network (2xGL-MV1000, GL-AR750, GL-AX1800). The network is started, but no connection to the other routers is possible; an exclamation mark appears for each router. (“0” receicved; “0” send). We have already stopped and restarted the network several times; we have also completely reset the network. The problem persists … What can we do? Thank you for your help.
P. G.

I think it’s not just you. This happens when the network is started