Did you encounter a specific message while trying to print the check? This will help us better to isolate the issue.
In the meantime, let's perform some troubleshooting steps. Try logging into your QBO account using a private browser. There are times that the browser is full of frequently accessed page resources, thus causing some errors and/or unusual responses.
To use a private browser, here's how:
On your keyboard, press Ctrl + Shift + N (Google Chrome).
Ctrl + Shift + P (Firefox).
Control + Option + P (Safari).
Once logged in, try to reprint your checks again. For your reference, you can also check out this article for further guidance: How to print checks.