If your wireguard connections says connected but you can't access any sites or just some sites you need to manually change the mtu settings in your config file, here is an example template:
You can change the number to try and get the best results.
[Interface]
mtu = 1380
Address = 10.2.0.2
PrivateKey = yourprivatekey
ListenPort =51820
dns = 1.1.1.1.,2.2.2.2
[Peer]
PublicKey = yourpublickey
AllowedIPs = 0.0.0.0/0
Endpoint = your.endpointvpn.com:51820