Windows 11 File Explorer could gain rounded corners as This PC white flashes are fixed
Microsoft is testing a minor UI refresh for Windows 11 File Explorer that would add rounded corners to the address and search bars (matching Settings), and it has acknowledged and patched the white-flash issue when opening This PC in dark mode; fixes are rolling out to Insider builds and should reach production soon, alongside other quality‑of‑life tweaks like easier theme switching from Quick Settings.