Something is fundamentally wrong.
I have put almost 70K miles on three trailers over the last nine years including some really bad roads (Only Afghanistan has worse roads than Mississippi.) and have never had to adjust the alignment.
I take them out to my buddy's shop every couple of years and they put the laser jig on the trailer. No changes required.
Now, I have wet bolts. I don't jump curbs. I run LTs at full pressure. My axle load is around 88% of rated capacity (10,300/12,000).
Sorry you are having this problem, but something is wrong.