PWAs fail to launch on my WoA (Arm64) environment

The useful comparison is that PWAs work in stable Edge on the same Surface, while both taskbar launch and the Dev app manager fail, and repairing Dev changed nothing. That narrows the investigation, but does not establish an Arm64-wide defect or a confirmed regression in the build you named. Update Edge Dev, record its full version and your Windows build, then create a separate Dev profile without importing extensions or settings. Install one affected PWA there and test it from that profile’s app manager. If it works, compare the original profile’s extensions and app installation; if it fails too, preserve that reproduction for Microsoft. Add both results and any relevant Application Error or crash details to your existing feedback. Use stable Edge’s working PWA installation meanwhile. Avoid deleting the original profile or app data before preserving anything important stored locally.