Hi there, John.
I'd like to know whether you have encountered any error messages while printing checks within the program. If so, please let me know the details of the error message to help me understand the issue better.
In the meantime, I'd like to suggest that you update your Adobe Reader/Acrobat software to the latest version or repair your Adobe installation, as most printing problems in QuickBooks Online (QBO) can be resolved by doing so.
Once done, I recommend setting up and printing checks again using a private or incognito window or another supported browser to determine if the issue is related to browser problems. QBO can occasionally behave strangely due to stored internet cache files.
If the problem persists, you may want to utilize our QuickBooks test drive to print a check to determine if you have any issues with your company file.
You can also run reports within the program to track the financial status of your business.
Kindly return if you require additional help with printing-related inquiries. You can let me know by commenting below, and I'll be happy to provide the you're seeking. Take care.