I'd be happy to assist you@angryatkwkbks.
First, let's fix the settings of the mobile app by uninstalling and reinstalling it. Go to the Settings menu in your phone and uninstall the app from there. Once finished, you can now reinstall the app and make sure you allow all the notifications.
You'll want to check out this article for reference: How to Download the QuickBooks Online mobile app. This will guide you to install/download app.
If you're using Quickbooks app for Windows, we need to make sure you've met these following requirements: QuickBooks app for Windows and Mac.
Regarding the blocker pop up error you encounter, There are updates will reset the pop-up blocker on your browser. Please follow the links below on how to turn this off:
If error still persist, please refer to this article for other basic troubleshooting steps: Troubleshoot printing paychecks, pay stubs, and forms.
Thanks for joining in the thread, @Psalm FM Radio.
We can go ahead and check the printing alignment of your checks.
Please check this article on how to align your check print.
Let's also make sure you have the latest version of Adobe Reader/Acrobat to ensure you'll not having any printing problem. I'm adding an article with additional insight on this:
Please let me know how this goes by clicking the Reply button in this thread. I'll be here to help you.