Modem stays "online" (all leds up) but its actually offline

Hi there my friends.

I have a question !

I have 2 modems, one legitimate and the other a 5101 with haxorware latest version.

Sometimes, both modems lose the signal and drop the connection.

The true modem shows (by their leds) that it indeed lost the signal (online power led ON and the rest blinking) but the modem with haxorware stay like its online (all leds firmly lit, and the ethernet blinking).

After the signal comes back, the original modem gets online straightfoward but the haxor one still there, thinking its online.

Anyone knows what might cause this ?

Thanks for the help