Inrush Current Limiter Failure
The inrush current limiter that you're using is under-specified and experiences too large of a temperature swing in your circuit. It fails due to excessive thermal cycling.

As expensive as it may sound, I've yet to find any inrush current solution more resilient than discrete resistors, and a contactor that bypasses them once the 24V control supply has started up. No need for any other delays: just a 24V switching supply, a contactor, and three resistors. The resistors would typically be in metal enclosures and mounted to a metal plate bolted to the DIN rail or the panel. You'd need to size them so that they can safely dissipate the energy they'll produce during the charging transient.