I would have to say no. First of all, the low pressure in front of the compressor (caused by the P-120) is going to be so low compared to ambient that atmospheric pressure is going to force plenty of air in the direction of the intake. Yes, it may be turbulent air, but centrifugal compressors are known for being VERY tolerant (much more so than axial) of turbulent air ingestion.

Perhaps the engine just hung-up, both times just in this situation. Or perhaps the engine is on the ragged edge of hanging up all the time and the slightly lower pressure during the high alpha passes kicks it over the edge into a hang up.

Whatever the cause, many HotSpots and P-120 combos have performed these maneuvers over and over again with no issues (I used to do it all the time with my HotSpot/TJT-3000 combo), so it is unique to your configuration (I would think). Could it be a fuel system issue when the nose is high and fuel is getting low? Let us know what you discover.