Big gap between server mtu and the client mtu any suggestions

[KOTRz]

Im getting this output when adding mtu-test

Jul XXXXXXX openvpn[58048]: NOTE: This connection is unable to accomodate a UDP packet size of 1601. Consider using –fragment or --mssfix options as a workaround.
Jul XXXXXXX openvpn[58048]: NOTE: Empirical MTU test completed [Tried,Actual] local->remote=[1601,1393] remote->local=[1601,1393]

Im getting the tunnel up and I can ping form the server the tunnel ip but I cant reach the lan at all, I have added all firewall rules and I suspect the reason is that the client is on a 4g connection that uses std class a lan ip of 10.X.X.X used by many 4g providers, I have tried any options but still the ping to the client lan from server and vice versa isnt possible,
I have noticed that server can ping the tunnel ip of client side but the client cant do.
is there a solution for this?