Client state as 'Offline' - Agent installed & connected

Hi,

I'm having a problem I'm trying to figure out for the last few hours..

Few of my clients are showing state as 'Offline', although the Endpoint agent is actually installed on the computers and is connected to the server as I can see in 'Troubleshooting'.

I cannot control them from SEPM.

I do get updates on the clients.

I tried to restart the client computers - didn't work.

I tried to search for clients, I did find them but they are offline.

I think that maybe the client IP has changed, but shouldn't that be updated in the sepm?

how do I update the client IP or refresh it somehow?