Only starts on second key turn???

Ok, so the starter on my 1993 4 cylinder standard truck will only turn over if you turn the key to the 'start' position, then turn it to the 'off' position and then back to the 'start' position. In other words, if you get in the truck and try to start it all you'll get is lights in the dash, but as soon as you turn the key 'off' and then try to start it again...it takes off no problem.

I've got a new battery (5 months). I removed the alternator and had it bench tested (works great) and I recently replaced the brushes in the starter.

By the way, the problem occurs all the time. It doesn't matter if the clutch is fully depressed or if the truck is in neutral.

So just what the heck is going on here? I could live with it, but I'm just worried that at some point it's not going to start on the second turn either.

Start simple and replace the starter relay. I have a 94 V6 4wd that did the same thing. Like a dumbass I bought a battery and a starter, when all I needed was a $10 relay

Well, the problem seemed to magically go away, but now it's back. So, I was told to give the starter a good crack with a broomstick handle and then give it a try. I did and it worked! In fact, everytime it won't start I give the starter a crack and then it works.

What's this all about? Solenoid? Starter? I replaced the brushed not that long ago.