I'm glad to have provided (at least a temporary) solution for your problems. However, you should read the modem information on DHCP carefully. It states that this DHCP is operational only under the condition that an external (bridged) connection with the cable is absent!
This means that this DHCP enabling/disabling can only affect your router connection, when your modem looses connection with the cable (possibly for only a very short period) and regains it immediately after.
The router(s) cannot handle two DHCP requests in a row and get stuck; your PC(s) do not mind.
The usual cause for loosing DHCP is the router failing to renew halfway its allotted lease-time, leaving it to the DHCP server to drop the connection. Given your repeat-time of minutes that is not a likely scenario.
Hence my request for your (modem and router) logfiles; I hoped to get some information from them about a fluttering connection/signals/signal to noise ratio or whatever.
Mees de Roo
Er bestaan 10 verschillende soorten mensen; de ene soort kan binair rekenen en de andere niet.