Wireguard internet connectivity issue

Hello,
I have setup Wireguard on ubuntu 24 on my hyper-v server connected to my home network with related port forwarding on my router.
I am able to VPN in using my phone and pc connected to a hotspot and also through cellular network here in the US with no issue . I can also browse the internet just fine , but my family in IRAN do not have internet even though they are connecting to my server with out any issue.
they just wont be able to browse the internet.
what can be the problem that stops them from being able to surf the internet as I do through my wiregurad VPN connection?

here are my server and client config file:

server:

[Interface]
Address = 10.0.0.1/24, fdd5:a3ac:a4fd::1/64
SaveConfig = true
PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE
PostUp = ufw route allow in on wg0 out on eth0
PostUp = iptables -t nat -I POSTROUTING -o eth0 -j MASQUERADE
PostUp = ip6tables -t nat -I POSTROUTING -o eth0 -j MASQUERADE
PreDown = ufw route delete allow in on wg0 out on eth0
PreDown = iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE
PreDown = ip6tables -t nat -D POSTROUTING -o eth0 -j MASQUERADE
ListenPort = 40443
PrivateKey = XXXX

Client configuration:

[Interface]
PrivateKey = xxxxx
Address = 10.0.0.2/24
Address = fdd5:a3ac:a4fd::3/64
DNS = 172.16.10.1, 8.8.8.8

[Peer]
PublicKey = xxxxxx
AllowedIPs = 0.0.0.0/0, fdd5:a3ac:a4fd::/64
Endpoint = my public ip address:40443

Hard to say but likely the have some firewalls in that country that are dropping certain types of encrypted traffic.

If the tunnel is up for them then this isn’t a country level blocking issue. Presumably they can ping your wg server & your gateway, along with the reverse.

It is odd that this setup works for you and not them. I would investigate what is different about their setup.

First a question: when you say they are connecting just fine, are they able to see any resources inside your network through the VPN?

The issue likely lies with internet access for your family in Iran after connecting to your WireGuard VPN.

Check for DNS settings