How big a hole are you making? What does the tip look like when you pull it back. If it were hitting something hard it should show up on the bit. Is there access to the inside? check it from there. Lastly make sure you're not low enough on the siding that you're hitting the foundation.

pictures?

"...drill bit I'm using from the outside is a wood auger bit..."

As soon as the tip hits anything much besides soft wood it will stop self-feeding and require anything from some pushing to forget it (not uncommon in old wood that has hardened over the years).

Try looking in the hole with a flashlight to see what the tip of the drill reached (or measure the depth and try and figure it out).

Plaster normally takes a carbide tipped masonry drill for clean holes (and not grinding the cutting edge off like with a twist bit).

I have changed bit to go through different materials many times.

There is no 'universal' drill bit that can always get through walls regardless of material (though a slow twist carbide tipped bit comes close).

Hopefully you are not hitting something important like a gas line, electric conduit, electrical box, water line etc.

I have been an avid Ham Radio operator for over 25 yrs (General Class call sign KC8UXZ) and over the years I have drilled dozens upon dozens of holes for antenna cables. In fact, to cover the entire ham radio spectrum with both omni directional antennas, directional antennas and experimental antennas I currently have 30 separate antenna cables from my shack.

Not once have I ever drilled a hole from the outside in. Lets face it, the final position of the hole on the inside is critical whereas no one cares where it comes out.

When drilling from the inside you can easily see where you might encounter electrical conduits, plumbing pipes, gas lines or structural metal components but when drilling from the outside its at best an educated guess if the hole will even ultimately end up where you need it.

Having said that, let us now consider the hole you are drilling. You stated that the house was built with lathe & plaster which means the house is most likely at least 40 years old. Now ask yourself, was this house resided? If so, is it possible that you are hitting old aluminum siding that is concealed under the new exterior finish?

If your drilling low are you sure you are not hitting an upper part of the foundation that is concealed behind a siding apron?

Hate to see the wall after the drill finally does come through. Drilling from outside through a plaster wall will likely knock quite a bit of plaster down, especially with an auger bit.

Long lost ham here too, (No-code, tech class KC0QMF). Sounds like you need a large conduit and LB for all those antenna cables :)