Wireguard connection drops after a couple of seconds

What you could try is to set up a wireguard server on the mango with the gui and compare in the lucy settings of the mango with the settings in your openwrt router.

Additionally, looking at the mango config and comparing it to the instructions on the page you linked, it also suggests to use 10.200.200.2/24 in the client app, while you have set 10.200.200.3/32, so if the instructions are right (which doesn’t fit to my working setting), you could try that.

Edit: I have to revoke to what I’ve written. My server also has /24 in the end.

My reading of the guide is /32 for peers –
In the PEERS section click Add and paste in the Public key you obtained from the wireguard app. In the Allowed IP’s section you’re indicating what addresses are reached through the tunnel to this peer. In our example we only want to send traffic to the one client’s address. To do this, pick an IP address for the client in the subnet you previously chose, and use /32 at the end. For example 10.200.200.2/32.–
I’ll try setting up a server on the Mango

You are right for the server configuration section, but the mango is the client and below it states:
Go back to the app and in Addresses , put the address you chose for the client and entered on the server in the peer Allowed IPs section, but use the real subnet mask (/24 in CIDR notation) like you did for the server Address, e.g. 10.200.200.2/24.

You are right, thanks for your patience. I get confused by peers, clients and servers in wg.

yup, i changed my wg server ip to /24 , still works

you specified your dns to ‘192.168.1.1’ is this your router’s local ip ?

DNS is specified as 192.168.3.1 which is the router’s local ip

I think the problem was that the Mango gui does not update all instances of the server IP. I changed my ddns service at some point in setting this up and looking at the config files the old ddns remained in the network section of the configs and so was different from that in the etc/conf section. Now all clients are working.
Thanks to all for the interest