I am having the problems described and posted a message yesterday. My annual service runs out in a couple of days and I cancelled to avoid automatic renewal.
Can’t add FIOS and can’t add YTTV. “No Login Form Found” is what I get.
FIOS was working fine until yesterday and then it totally died.
I’ve used Channels for a few years and am sad to leave. YTTV w/out Channels seems to be my path forward.