Lifter tick?

[nickyyG]

I own a 2018 Silverado with 85k on it. While driving I heard a sudden ticking sound coming from the motor. Occurs at idle and increases with rpms, doesn’t go away after truck is warm. Sounds like the drivers side. Oil pressure was 40 at idle, oil levels were correct and oil itself is still golden, no check engine light. I popped both pass and drivers valve covers to check for collapsed lifter, but all the rocker arms are functioning nicely with no slack when turned off. Wondering where I should look next?