Sorry to hear you are having issues. It is known that some Universal Application don't work well with Curtains. What you can do is to tel Curtains to ignore that application and don't skin it. Some application are not skin by default. But you can also to have if force disable it. Refer screenshot below. By default MS Store is disable. BTW, I am on Curtains V1.2. So there might be some differences in V1.19.
Stardock Community Assistant.