Client can't ping one of multiple server networks

Hi,

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I have a configuration with a central server connecting 2 networks.

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Here is the configuration:

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Main server have ip 10.89.0.1 (Scaleway instance)

First site have ip 10.89.0.2 (random amd64 debian)

It can expose 2 sub-nets: physical network (192.168.0.5, the physical ip of the pc) and a libvirt network (192.168.125.1, bridge for all virtual interfaces)

Second site have ip 10.89.0.4 (synology, with self-compiled wireguard)

It can ping the physical network but not the libvirt network.

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Fun thing:

10.89.0.1 can ping both network without problems

another random pc i used (let's say with ip 10.89.0.3, a random raspberry pi) can ping both network without problems. Same conf file (except private key and vpn ip)

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Is there any tool to debug this?

Edit:
iptables were cross-checked and seems ok (never making limitation by source ip, only by interface)

routes are fines too