I am facing the exact same issue. Just turned on 2FA on our RBC business account yesterday. This caused me to receive a phone notification at 6 AM to authorize login. I had no idea what this was about until I logged into QB and noticed that bank account was no longer connected. You guys need to talk to RBC to figure this out; there is zero reason for us to keep using QB online if we can not keep our bank accounts and credit cards synched with it.  

Are there any Canadian banks that QB doesn't have same issue with that actually support 2FA? Not having 2FA enabled for business bank account is opening a giant security issue.