Issue With Aftermarket Water Temp Sensor

So, I recently bought a set of aftermarket gauges and I have everything almost entirely wired up the way it needs to be. The last piece is installing the aftermarket water temperature sensor. I was going to put it in the 1/8 inch port on the front drivers side of the intake manifold. The new sensor that comes with the aftermarket gauges is 1/8–27 NPT. I believe the factory sensor is the same size and thread pitch?

I have a brand new factory style replacement that threads in all the way, but I can’t even get the threads started on the new aftermarket sensor. The threads look fine on both. I took both of the sensors to the hardware store near my shop and the factory style threaded all the way into a fitting they had at the store, and the aftermarket one only threaded about three or four times before the taper wouldn’t let it go any tighter by hand.

The threading looked a little shallow on the aftermarket temperature sensor, so I’m thinking maybe that’s why I can’t get it started? Either that or the threading is actually BSPT or something weird like that. Any ideas or insight?

Sure bout that?

There's a 1/8 BSPT that isn't the same as NPT

Factory style is the bronze one. Aftermarket is the aluminum one.