In fact the router has 192.168.1.1 as IP address, airport base has 192.168.1.110 and the macbook 192.168.1.104.
Why do you believe that putting a random IP address will solve the problem? isn't the IP address chosen by the router?
maybe do I have to set a manually configured routes?
Because I understand networking, or at least 15 years ago I did. you don't apparently.... Its the first step ANYONE would tell you. Its not a randomly chosen IP.
Its an IP address that IS on your subnet (assuming you have a typical class c address) that is NOT in your DHCP range.
There is a good chance your router and MIAMI are simply incompatible as far as DHCP. Hell, my Miami setup fails to get an IP address probably randomly 10% of the time... DHCP is not required and your Amiga will work just as well, with a STATIC IP.
Maybe the others will help, but i will provide no further assistance until you at least TRY what I say.