is20 swap overboost issues

I've been getting a p023400 overboost code whenever I'm on the freeway. I have a slushbox and am usually in 3rd or 4th and go WOT from about 50mph. I get an EPC light, lose all boost, and it will go back to normal once I restart the car. This never happens if I get WOT from a stop, only in those conditions.

I am APR tuned.
APR downpipe
Brand new IS20 turbo
034 Motorsports intake
APR turbo inlet pipe

This happen to anyone else? Also any idea what could be causing this?

Thanks

Did you ever find a solution for this? I have the same symptoms on a DSG 4Motion 1.8 with Unitronic IS20 software