On Wednesday 12 June 2019 23.33:11 Mike Bird wrote:
> Hi Thierry,
>
> If your smart phone can access your server and your LAN cannot a
> possibility is that IPv6 is working and IPv4 is not, or vice versa.
>
> Try "traceroute -4 ..." and "traceroute -6 ...".
>
> --Mike

Thanks Mike, but it was not that (I don't use IPv6). I solved the problem by 
changing my router's mac address, that seemes to have been blacklisted by the 
server somehow.

Thierry