My app uses SwiftUI Map and draws Markers, MapPolyline and MapPolygons over it. These all work on actual devices. On the iOS 26.0.1 Simulator running on macOS 26.0.1 Polylines and Polygons do now show.
Do others see the same thing?
MapPolyline and MapPolygon not visible on simulator
Do you get the same results with just the relevant code in a small test project? If so, please share a link to your test project, or share the SwiftUI view code here, along with screenshots for what you see. That'll help us better understand what's going on. If you're not familiar with preparing a test project, take a look at Creating a test project.
— Ed Ford, DTS Engineer
Thanks Ed for the prompt. Hmm, it works in a small demo project so it's my problem somehow. I'll try to narrow it down.