I think DX Engineering has done a great job of making a very simple antenna complicated.
The "old time" Hustler instructions for a 5BTV (liek 40 years ago) was: Put it up, add radials, adjust the tubing lengths for minimum SWR on the frequencies of choice," and that was pretty much it. They worked great, simply following those instructions.
You tune up each band from 10m to 80m, one by one, starting with 10m. The tubing lengths all adjust a lot in length just loosening the clamps and re-tightening them. Sounds like you're way off on 15m because the tubing between the 10m and 15m traps is set too long. Change that. 80m is usually the "last" adjustment you'd make, after everything else is done, and is adjusted by the whip length above the loading coil.
It's a really simple antenna.
What if soy milk is just regular milk introducing itself in Spanish?