I've been having a similar problem: I filled out my info (including auto fill from CRA) then my spouse tried to fill out hers but TTax keeps saying I "may still be logged in" to CRA. I'm not. I've also cleared my cache and tried a private browsing session. No luck. I tried asking for help but the maddening help-bot refuses to patch me through to a human being because it thinks all such requests are for tax advice, which I haven't paid for. The bot seems to have no ability to recognize I have a basic technical support question. I'll try the link you provided, but the bot needs fixing.
