We'll start with the browser troubleshooting first to print your checks correctly again, treasurer100.
Refresh your QBO by clicking the Reload option in the upper right-hand corner. You can also do this by pressing CTRL + F5. Then, close and reopen the program to start a new session with QBO.
If you get the same results, you can try printing the checks using a private browser. This will help us know if the issue is cache related. If the checks print correctly, go back to your previous browser and clear the cache. I'd also suggest switching to Google Chrome, Internet Explorer, or Mozilla Firefox to do this task.