I am having this same issue for about 3 months.  I bank with Capital One.  I called them and they informed me that they made security upgrades and QBO likely does not meet their security requirements.  So I have to relink to my accounts every time I want to pull in transactions and update my books.  One of these vendors will be getting FIRED.  I have not decided if it is QBO or Capital One yet.   When you call support they each blame the other vendor.  So frustrating.  And with continually increasing pricing with QBO I am tempted to fire them!