Earlier this year, Mixed Reality Toolkit (MRTK) users identified a bug that caused MRTK menus to disappear from view when they were unpinned. This happened if an MRTK project was built in Visual Studio using ARM64 & Release mode, and deployed to a HoloLens 2.
See the original Github issue here, NearMenu/RadialView/Solvers break in ARM64 Release mode.
As of Visual Studio 2019 v16.8, this bug is now fixed! Please update your version of Visual Studio 2019 to version 16.8 or later, to continue using ARM64 Release mode builds.
See the the Visual Studio Developer Community post here.
