SSL VPN - Cannot access most of the remote devices

Hello,

I just installed a SG115 at a customer site.

External (Internet) access and redirections (DNAT) are working fine.

I also configured a SSL VPN (as usual, as described in https://community.sophos.com/kb/en-us/116038).

The VPN connection is established without any problem, I receive an address in the VPN range (10.242.2.0/24).

But... most of the devices in the remote network (192.168.75.0/24) cannot be reached (ping, http, https...)

There are (in the remote network) some very basic devices,  managed via a basic (without specific security) HTTP interface but they cannot be reached.

But some other can  : I can connect to 192.168.75.207 but I cannot connect to 192.168.75.3 (both have a basic HTTP interface).

Another Sophos UTM (192.168.75.2) can be reached via https on port 4444.

Same problem with ping : 192.168.75.207 can be ping, but 192.168.75.3 not.

Same issue with network discovery : about 1 device out of 4 can be discovered, other not.

Do you have any idea about the problem ?

thanks in advance for your help.