I’m having exactly the same issue, spoke to a QBO representative yesterday and this morning I have rung and spoke to ANZ ….. it’s a viscous circle ! QBO Blame ANZ  for security update and ANZ are saying there end is fine and no errors are appearing, my bank feeds are all fine !! 
just a fantastic situation to be in and I’ve deleted my linked accounts in QBO thinking that would resolve it and I am now unable to re add them due to this issue 😖 

hope a resolution is found quickly !