Hello, Djay0542. 

Let's isolate this case by perform basic browser troubleshooting by clearing the cache to fix the issue.    

There are times that the browser is full of frequently accessed page resources, causing some unusual responses. We can start by accessing your account in a private browser. This mode doesn't save your searches, visited pages, log-in details, and cookies.    

You can use the shortcut keys that I've listed below.  

• Ctrl + Shift + P (Firefox) 
• Command + Shift + N (Safari) 
• Ctrl+ Shift + N (Google Chrome    

If it works, then you can go back to your original browser and clear the cache. Alternatively, you can use other compatible browsers. It could be that the one you're currently working on has a temporary issue with QuickBooks.   

Here's a step-by-step guide in reconciling your account in QuickBooks Online: Reconcile an account in QuickBooks Online.

Also, learn what to do if your account in QuickBooks Online doesn't match your bank statement at the end of reconciliation: Fix issues when you're reconciling accounts in QuickBooks Online.

Feel free to ask questions if you need clarification. I'll be happy to assist you further. have a great day and stay safe!