Huh strange, it seems it was the 150% spring causing the problem. I guess when the slide racks bad, the force going back to the front must lodge the BB a little further up causing the BB to go over the hop-up.
Switched back to the stock spring and the slide has a hard time locking back with an empty mag due to the slide being heavier
Now what can I do to get the 150% working without it pushing the BB to far out? Should I sand the nozzle a wee bit, or cut the spring a little?