Can't ping some remote server from fortigate

Hi,

Since the end of last week I can't ping some of my remote servers.

I have a remote network, I can ping machines (exemple 10.148.31.1) but I can't ping others (exemple 10.148.36.2) If I am connected directly in the remote network (from vmware), I can ping and access to all machines (tested a ping from machine A to B, B to C, ....). I tried an execute ping from my fortigate and it also failed for 10.148.36.2 Do you have an idea ?

Regardsn