Same problem, i have TP link wifi router and when i have electric cut, i have no more Internet, i have to reboot manually the modem, i am sick of this. If you have any solution please share.
It do get rebooted sometime but stuck on red light then and in any case have to reboot.
It is important to mention that Router (local conenction) never disconnect, TP linkk work alway, i never needed to reboot it.
It is the PTCL modem that stop working till i reboot it.