Before the reinstall, you hadn't ever had a total freeze of the application, correct?
Besides recommending a reinstall the other two things we often check are if the app is up-to-date (which you can check by heading to the Apple App Store and seeing if there's an update pending) and what OS version you're using.
Would you be able to let me know what OS version you have, and which model of iPad you're using?
Let me know how I can help!
Have a good day!
Shopify Guru | firstname.lastname@example.org