Looking for some advice...

My Audi is a chipped APR Stage 2+ and runs like a champ. However, I have noticed lately that my boost gauge (Equus 8000) is fluttering under heavy boost, like 2-3psi

I have since checked and replaced all vac lines, replaced crank brth hose, replaced PRV, and inspected the intake side as well. Looks all good to me.

Question is... What could be causing this flutter? Could be the gauge?

The gauge seems to be working correctly... When off, it sits at ZERO. When at idle it is between 14-17 (normal for high altitude: 7000+). This is not fluttering at idle...Depending on where I am at on alt, its stable. Only flutters on high boost.

The only reason I purchased the gauge is for troubleshooting. The Div Valve is an APR R1 and appears fine. Problem is... where should I look.

Thanks