Intermittent Clicking

Hi all, I've had the WRX for a year and 5k miles, it is a mechanically stock 2015 FA20 with 85k miles and a mild Bren E tune, it just developed an intermittent ticking sound after a hard pull up to rev limiter.

The Cobb AP indicates no knock (DAM is 1.00) and not throwing any codes. The intermittent ticking sound is a fairly loud engine noise, sounds like a complaining lifter/rod around 2.5-3k rpm that is only noticeable when engine is unloaded or bearly loaded. Nothing visual on engine, oil, coolant and exhaust are clean.
Any thoughts or suggestions would be very welcomed.