I've lost the ability to show a check cleared and reconciled. Can someone tell me how to get that back?

I'll make sure you'll get your ability back to show cleared and reconciled checks in QuickBooks Online (QBO), @sandy84.

You'll first have to ensure you're logged in as an admin (Company or Master) user to access every part of your QuickBooks account. Then, verify that the check's account category isn't updated. Visit the Audit Log page to track activities and see who made changes to your books.

Once you're done, you can go to your account's register from the Chart of Accounts page. Make sure to enable the Reconcile and Bank Status column. This way, you can view all your transactions, including checks and their status (i.e., C - Cleared and R - Reconciled). Here's how:

1. Go to Accounting from the left menu.
2. Select Chart of Accounts.
3. Locate your account. 
4. Click View register from the Action column.
5. Tick the small Gear icon above. 
6. Choose Reconcile and Banking Status column checkbox. 
7. Click the small Gear icon again to clear the options. This will display the Checkmark column in your account register. 

Then, once you need to review your transactions or make quick edits, you can use the filtering and sorting tools to speed up your search. You can refer to this article to know more about this: Find, review, and edit transactions in account registers.

Also, I'd recommend reconciling your accounts every month. This way, you can monitor your income and expenses and detect any possible errors accordingly. For the step-by-step guide, you can check out this article: Reconcile an account in QuickBooks Online.

Please don't hesitate to keep me posted on how it goes in the comments below. Let me know if you have other concerns about managing cleared and reconciled checks in QBO. I'll gladly help. Take care and stay safe, @sandy84.