QBO stopped updating checking account 5 day's ago, why?

Nice to have you in the Community space, @usersales1.

I'd like to help and get this issue sorted out right away. Can you share with me the name of the account you're having issues with? Any additional information can help us narrow things down.

In the meantime let's manually update your bank to download the latest transactions. Let me show you how.

1. Sign in to your QuickBooks Online (QBO) account and go to the Banking or Transactions menu.
2. Select Update a couple of times to refresh the connection. 
3. Enter your Multi-Factor Authentication (MFA) if asked.
4. Then select Continue update.

You can also check this article for more details: Download the most recent bank and credit card transactions in QuickBooks Online.

If this is not the case, you'll want to manually upload your bank transactions. Also, I'd recommend contacting your banking institution and verify if there are any issues on their end. 

Once everything is in place, you can now categorize and reconcile your accounts whenever you're ready.

Keep me posted if there's anything else you need help managing your transactions. I'll be around ready to back you up. Have a great week ahead!