Odd engine behaviour at T+ 35 seconds

[Calvin-13]

35 seconds after I started the engines (Three Restock Swivels) on a rocket via staging, they began rapidly flickering on and off, causing the vehicle to lose altitude. Restarting the engines manually or turning off this mod's features through their PAWs made no difference. As well, reverting the flight, loading a quicksave, or recovering and trying again did not cause any change, and the event still occurred. Upon staging the rocket, the same thing happened to the engines on that stage (Two Restock Terriers). This did not create any log entry or screen message, and always occurred at T+ 35 in-game seconds, even if I timewarped. I was unable to fix this without uninstalling the mod.