Could you provide IBIS model for ADuM1412?
Because my customer need estimate timing specification with PCB trace.
It's possible that a transient on the +5Va supply is inducing latch-up. Can you see any disturbances on this line at the ADuM141x VDD pins? The 100 nF decoupling caps should be on the same side of the board as the IC and as close to the VDD pin as possible…