Hi there! I understand you're having trouble with the T.J.Maxx app on your Mac running OS X 10.15.7—specifically, when you tap "Shop," you just get a blank page. Let's get that sorted out.

To start, can you tell me if this issue happens only when tapping "Shop" or are other parts of the app affected as well? Also, have you tried reopening the app or restarting your Mac since this started happening?

Meanwhile, here’s a step-by-step approach to troubleshoot this:

1. Check for App Updates: Sometimes a blank page can be due to the app needing an update. Since you're on a macOS device, confirm that the T.J.Maxx app is updated to the latest version via the App Store.

2. Quit and Relaunch the App: Fully close the T.J.Maxx app, then open it again. This refreshes app data and might resolve temporary glitches.

3. Clear Cache/Data: On a Mac, app cache clearing is less straightforward than on mobile, but you can try uninstalling the app and reinstalling it. This often clears any corrupted temporary files causing issues.

4. Check Internet Connection: Make sure your Mac has a stable internet connection since a blank page can be due to network timeouts.

5. Try Using the Website: As an alternative, you can try shopping directly at tjmaxx.com via your browser to see if you experience similar issues there.

If these steps don’t fix it, the issue might be deeper, such as account-related or a known app bug. I can help you escalate if needed or provide more advanced steps. Also, if you're comfortable, let me know if you've tried any of these steps already, so I don't repeat them.

Are you able to perform these steps? Let me know how it goes!