Hi BarryM_,
Thank you for reaching Microsoft Community. We're sorry for the trouble this has caused you.
I just want to confirm when you say adding items to the Microsoft Office Cart, do you mean Microsoft Store online through web? (a photo of the issue would be helpful)
I would need an answer to this question to provide accurate resolution. For the meantime try the following steps below.
1. Force the device to shut down and restart
Press and hold down the power button until your Surface shuts down and restarts and you see the Windows logo screen (about 20 seconds), then release the power button.
2. Run Surface Diagnostic Toolkit
See: Fix common Surface problems using the Surface Diagnostic Toolkit (microsoft.com)
3. Run the system file checker to check if there are corrupted system files that are just looping around causing this kind of issue to exist. To run the system file checker, kindly type Command Prompt on the search box next to the Windows icon and run it as administrator. Once done, type and enter sfc /scannow.
Let it load, detect and repair those corrupted files. Whether it detects a corrupted file or not, kindly restart your Surface device afterwards..
Kind regards,
Lavenia