Second brand new Holley carb flooding?

Yes, but if it was an electric fuel pump with too much pressure, it should happen all the time, not intermittantly...

Most likely something before the carb causing the issue letting dirt in the needle and seat.

Not necessarily. If the fuel pump is putting out a pressure that's close to the upper limit for the needle and seat, then the needle and seat might work sometimes and only get blown off occasionally when the fuel pressure spikes up a little or conditions in the carb create an issue. That would appear to be random/intermittent.

What is the fuel pressure?