Ja tez mam ten sam problem.
Moze znalazlem rozwiazanie:
"What worked for me
I was having the same problem with the F5D7230-4. I decided to try an experiment and it worked: first, connect your PC directly to the modem, bypassing the router. Open a command window and type 'ipconfig /all', then write down your current IP and the IP's shown for the subnet mask, default gateway, and DNS servers. Then, after reconnecting the router, go to the embedded web page configuration tool (192.168.2.1), select 'Connection Type' under 'Internet WAN' and choose 'Static', even if you don't have a static IP. Enter the information you just wrote down in the following pages (why two?) and apply the changes. You should see 'Connected' in the upper right after the router restarts. If so, go back to the 'Connection Type' again and choose 'Dynamic'. The router will maintain your internet connection, even if you power it down and back up.
Hopefully that will help someone else who like me was ready to throw one of these devices through the window!"
Wieczorem sprawdze czy to rzeczywiscie dziala!