Problem in my network

Hello everyone
In my Head office I have a peplink balance 580 and in my branche office I have a peplink balance 30 pro.
Everything use to function correctly, just 2 days ago,
I noticed that the branch office could not more reached the head office, I noticed that the peplink of the branch office is quiet online on the ic2 plateform.
I noticed that in the head office I can ping the WAN interface of the branch office peplink and I can connect myself to the peplink but I cannot ping the LAN interface nor connect myself to it…
Please I need your help

Go to the status > Speedfusion screen on both devices. What do you see?
Check the event logs on InControl for both devices - what changes have happened in the last 2 days?

Are all the WAN connections green / healthy?