I had the same issue and I believe I figured it out. Building in the editor most likely refers to Live Coding. Make sure you have Live Code enabled in your editor preferences (note that this will no longer allow you to build using VS while Live Coding is enabled) and then press ctrl + alt + f11 to summon Live Coding. This should start the build process in the editor and refresh the editor screen, omitting the need to restart your editor to see the changes you made to any UPROPERTY modifiers.