Lutron MS-OPS5M-WH Maestro wired with 3 way mechanical switch as per instructions.
It works from both ends (mechanical and button press, as well as occasional blinking) as expected when outside wall box with wiring pushed back into box. However, when the switch is screwed down, the switch continues normal function for a few minutes, and then nothing from either end (mechanical switch, push button, or sensor).
No obviously loose connection or broken conductor when using the non-contact voltage sensor. All grounds appear to be tight.
It's the "works outside the box" and "works for a while" in the box that has me confused.
Any ideas?