We can connect hundreds of financial institutions in QuickBooks Online. Let me help you with BECU.
I checked our records and found an investigation regarding the BECU Business Online Banking. Currently, they are checking and fixing the cause of why you're unable to log in and connect. I suggest you reach out to our Support Team so they can add you to the case and will receive updates.
Click the (?) Help icon and enter Talk to a human (then type it again when prompted).
When asked by the bot, enter "BECU Business Online Banking".
Select I still need a human, then proceed with Contact us or Get help from a human.